net-im/gajim: update to 2.0.1

- update to 2.0.1
- switch to gtk4
- chase spelling library change
- remove commented gupnp dependency - it's implemented via gobject anyway, but
  still disabled in gajim's source

Release notes:
https://gajim.org/post/2025-02-28-gajim-2.0.0-released/
https://gajim.org/post/2025-03-03-gajim-2.0.1-released/