Zypper performed the upgrade anyway:
3400g:~ # zypper if openSUSE-release
Loading repository data...
Reading installed packages...
Information for package openSUSE-release:
-----------------------------------------
Repository : openSUSE-Tumbleweed-Oss
Name : openSUSE-release
Version : 20240613-2951.1
Arch : x86_64
Vendor : openSUSE
Installed Size : 223.9 KiB
Installed : Yes
Status : up-to-date
Source package : openSUSE-release-20240613-2951.1.src
Summary : openSUSE Tumbleweed
Description :
openSUSE Tumbleweed is the rolling distribution by the openSUSE.org project.
3400g:~ #