Update gtk-sharp3

[cleitonbueno]

Description:

I propose updating the gtk-sharp3 from commit 9a72bb67fff7e4845b7bb430a608282668c3e4da to the latest commit dadc19cf1b90c5743f2776c675faac990e397a56.

This update brings important compatibility improvements and build fixes.

Key changes included:

• Change default branch from master to main.
  Commit a00552ad

• Fix compilation error:
  CS0030: Cannot convert type 'Gtk.VScale' to 'System.Range'
  Commit a00552ad

• Fix build issue with newer Mono versions, fix this Issue #151
  MONO_PROFILE_ENTER_LEAVE undeclared
  Commit c1b9bd42

• Replace usage of mcs with csc for building, and remove the patch (0001-fixup-gmcs-to-mcs.patch) that does this.
  Commit 05e47a49

• Add gtk-sharp3 in test-image-mono image.

[ajlennon]

Sounds good!

[ajlennon]

Any thoughts on a PR for this @cleitonbueno ?

[cleitonbueno]

Yes, #263

[ajlennon]

Thanks for the pointer - will get this going too