Tested on a Mac mini M1 with macOS 12.4 with Safari WebKit Build Archives 251224@main and the error and stack trace is the same. Also tested after creating a new user on this machine (no Apple Id login) so the user settings are not a factor here.

NOTE: You may need to create a new macOS user to reproduce this issue.

Amending some details above. The bug happens on all 3 environments noted above. So macOS 13.6.4 with Safari Version 17.3 and newer seem to be affected by this bug. Create a new macOS User if you can't reproduce. (bug seems depended on macOS user setting or state)