Bug#992907: gtk4: release to unstable

[Simon McVittie]

Source: gtk4
Version: 4.4.0+ds1-1
Severity: wishlist
X-Debbugs-Cc: debian-gtk-gnome at lists.debian.org
Control: block -1 by 992857
Control: block -1 by 991964
Control: block -1 by 992906

We should get gtk4 into testing/unstable during the bookworm cycle.
Until a new 4.6.x stable branch starts, I think we should avoid uploading
4.5.x to experimental, and instead get 4.4.x into shape for testing/unstable.

Blockers:

- Needs a new wayland-protocols: #992857

- Needs a new pango: #992906

- We should fix the incomplete move from @substitutions@ to debhelper
  environment variable substitutions: #991964

- For at least initial uploads to unstable, I think we should disable
  FFmpeg and Vulkan, both considered experimental upstream (I've disabled
  FFmpeg for uploads not targeting experimental, and Vulkan entirely)

- Do we want to disable the Broadway backend? It's not clear to me that
  anyone actually uses Broadway - it seems more like a proof of concept
  than something genuinely useful. Perhaps we disable it until someone
  asks for it to be enabled?

Anything else?

    smcv