Thank you, Tannington!
The results, after another DUP:
sudo cat /var/log/zypp/history | grep -i nokey
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Extra/noarch/smplayer-skins-20.11.0-1.9.noarch.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Extra/noarch/smplayer-themes-20.11.0-1.12.noarch.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Multimedia/x86_64/libdriveio0-1.16.4-1.19.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Multimedia/x86_64/normalize-0.7.7-4.54.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Multimedia/x86_64/libmmbd0-1.16.4-1.19.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libx264-161-0.161+git20200912.d198931a-2.22.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libquicktime0-1.2.4+git20180804.fff99cd-4.51.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libfdk-aac2-2.0.2-1.10.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libopencore-amrnb0-0.1.5-1.66.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavutil55-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libfaad2-2.10.0-1.21.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libde265-0-1.0.8-1.20.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libopencore-amrwb0-0.1.5-1.66.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libgstphotography-1_0-0-1.18.5-5.5.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libopenaptx0-0.2.0-10.11.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libfaac0-1.30-1.28.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libvo-amrwbenc0-0.1.3-1.55.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavutil56_70-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libx265-199-3.5-2.19.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libdca0-0.0.7-1.31.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libxvidcore4-1.3.7-1.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/flash-player-32.0.0.465-3.10.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/librtmp1-2.4.20151223.fa8646d-1.75.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Multimedia/x86_64/dvgrab-3.5-13.93.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libswresample2-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libpostproc54-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libswscale4-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavresample3-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libsox3-14.4.2-7.92.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libswscale5_9-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libswresample3_9-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libpostproc55_9-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavresample4_0-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libheif1-1.12.0-3.16.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavcodec57-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/sox-14.4.2-7.92.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavcodec58_134-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavformat57-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavformat58_76-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavfilter6-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Multimedia/x86_64/transcode-1.1.7-11.31.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libvlccore9-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavfilter7_110-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavdevice57-3.4.9-1.3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libvlc5-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/libavdevice58_13-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/vlc-noX-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/ffmpeg-4-4.4-9.4.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/vlc-qt-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/vlc-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/noarch/vlc-lang-3.0.16-4.27.noarch.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/vlc-codecs-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/vlc-vdpau-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY
# warning: /var/cache/zypp/packages/openSUSE_Tumbleweed/Essentials/x86_64/vlc-codec-gstreamer-3.0.16-4.27.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 1abd1afb: NOKEY