So here is when it happened. I wonder, do you remember any zypper questions about conflicts similar to what you got today?
What happened today is due to the change in NVIDIA repo package (actually, bug fix strictly speaking):
Fri Apr 26 16:41:00 UTC 2024 - opensuse-releaseteam@opensuse.org
- NVIDIA package needs to require specific flavor. Issue #53
So you already had wrong flavor of NVIDIA repo package for quite some time but it did not cause any issues because it required openSUSE-repos which was satisfied by openSUSE-repos-Tumbleweed. But now it explicitly requires openSUSE-repos-MicroOS. Same issue with Slowroll.