Some Unicode characters in domain name result in "Invalid Address"

Versions

• OS: Debian Linux
• Gajim: 2.4.6
• GTK: libgtk-4-1:amd64 4.22.2+ds-2
• python-nbxmpp: 7.2.0-1

Steps to reproduce the problem

1. Try to add an account or talk to a user on xmpp:☝️.op-co.de
2. The JID is shown as "Invalid Address"
3. Changing ☝️ to ツ (both are working XMPP domains and both are Unicode 1.1 characters) makes the JID "valid" again

Expected behavior

Characters from Unicode 2.0 (probably even 3.2) should be valid, unless excluded from the nameprep profile.

• XMPP: Address Format and IDNA require domain parts to match nameprep
• Nameprep lists the respective tables from stringprep
• stringprep does not exclude or impose special treatment on the ツ U+30C4 or the ☝️ U+261D characters