[gdk-pixbuf] (16 commits) Non-fast-forward update to branch ebassi/gi-docgen

[Emmanuele Bassi <ebassi src gnome org>]

The branch 'ebassi/gi-docgen' 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:

  6dcfdc8... docs: Fix the deprecation annotation for AlphaMode
  af28805... Fix inclusion guards for gdk-pixbuf-features.h
  d2e3ace... Port gdk-pixbuf to gi-docgen
  9bda325... docs: Port to the gi-docgen syntax and style
  5126dbe... docs: Generate the GdkPixdata API reference
  19aeb66... ci: Update the Docker image
  a54b9a0... ci: Update reference and dist jobs
  f18ac1d... docs: Clean up GdkPixbuf's core API
  8b0aed9... docs: Update gdk-pixbuf-io style

Commits added to the branch:

  69fc557... build: Fix syntax for has_function() (*)
  0a670de... docs: Fix the deprecation annotation for AlphaMode
  073a947... Fix inclusion guards for gdk-pixbuf-features.h
  0c545e3... Port gdk-pixbuf to gi-docgen
  0ad5532... docs: Port to the gi-docgen syntax and style
  9de2b14... docs: Generate the GdkPixdata API reference
  baf188d... ci: Update the Docker image
  5030bb1... ci: Update reference and dist jobs
  63e3081... docs: Clean up GdkPixbuf's core API
  f2a1123... docs: Update gdk-pixbuf-io style
  27f5e96... docs: Update pixdata style
  1dd020c... docs: Update pixbuf-data style
  8faf466... docs: Update pixbuf-util style
  3b49374... docs: Update pixbuf-scale style
  d2cb184... docs: Update pixbuf-animation style
  f75f9bf... docs: Update pixbuf-loader style

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