[vala] (8 commits) Non-fast-forward update to branch wip/issue/606

[Rico Tzschichholz <ricotz src gnome org>]

The branch 'wip/issue/606' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  de9b1f7... WIP girwriter: Infer gir_namespace/version from target GIR 
  de2a9ec... WIP build: Generate GIRs for libvala

Commits added to the branch:

  bed0291... girwriter: Only replace existing GIR files if they changed (*)
  b9085f2... gtk4: Update to 3.94.0+724ec3ca (*)
  6d63ab1... gstreamer: Update from 1.17.0+ git master (*)
  6c75818... vapi: Update GIR-based bindings (*)
  96e55fe... compiler: Add OptionFlags.NO_ARG to deprecated "--thread" o (*)
  adca296... WIP girwriter: Infer gir_namespace/version from target GIR 
  0d65cc8... WIP build: Generate GIRs for libvala
  c0f553b... WIP build: Check for valac with sufficient GIR support

(*) This commit already existed in another branch; no separate mail sent