Been running the new kernel 6.17.0-19-generic for a few days now without any issues... But I did see this message in the logs and have NOT seen it before the update:
This would be caused by a specific GTK application, not by the kernel. That is a bug in that application and on Zorin OS with Gnome, that leaves a lot of possibilities as to which is the culprit.
Do You have any active Problems or does the System run fine? If it runs fine, I think, You can pack this aside. Not every Log Entry does automatically mean that You have directly an affecting Issue.
Ran "journalctl --user -b | grep "g_hash_table_foreach_remove_or_steal" this morning after booting up and nahda (no output)... so it appears fine and maybe that was just a rare glitch