Hi!
1041703 Broken due to missed udev dependencies
https://bugs.debian.org/1041703
Otherwise no keyboard and mouse input in sddm or lightdm (and likely other
display managers), no working fwupdmgr and likely other issues and crashes.
libgudev maintainers raised minimum libudev version which currently breaks
with libeudev. I hope they will not do that too often (at least not without
coordinating with libeudev maintainers).
In case you updated already
https://ftp.debian.org/debian/pool/main/libg/libgudev/libgudev-1.0-0_237-2_amd64.deb
should fix the issue.
Boot into recovery mode and install from there.
Best,
--
Martin