[libadwaita] (40 commits) Non-fast-forward update to branch wip/exalm/headerbar-fix

[Adrien Plazas <aplazas src gnome org>]

The branch 'wip/exalm/headerbar-fix' 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:

  6a5bd2f... header-bar: Set focus funcs for the gizmos

Commits added to the branch:

  8f43497... readme: Update the matrix room link (*)
  3f0df1a... meson: Avoid a trailing slash on libdir and datadir (*)
  9e4ac48... preferences-page: Support mnemonics (*)
  72091ef... view-switcher-button: Support use-underline (*)
  e086fa0... preferences-window: Strip underlines from search view rows (*)
  77243b8... demo: Add mnemonics to preference pages (*)
  5dfc25b... readme: Update links (*)
  4f6e828... doap: Add Alexander (*)
  fdabe76... Update POTFILES.in (*)
  aab6c89... Update Ukrainian translation (*)
  a12ac7a... Update Brazilian Portuguese translation (*)
  a8bb102... Drop duplicate icons (*)
  dc5914b... ci: Add ABI checker (*)
  5601880... ci: Work-around libabigail bug (*)
  879bb6e... ci: Work-around another libabigail problem (*)
  5c7741f... ci: Move API visibility script to .gitlab-ci/ (*)
  34b521e... ci: Use a container image for abi checker (*)
  24ebbc4... leaflet: Fix ordering in children_reversed (*)
  cd8f3a2... Stop translating properties (*)
  8269f69... shadow-helper: Remove a stray backslash (*)
  7ca8e64... preferences-window: Use gtk_widget_get_ancestor() (*)
  364afff... preferences-window: Fix a build warning (*)
  785618d... preferences-window: Refactor new_search_row_for_preference( (*)
  2e9ab64... preferences-window: Get the number of pages manually (*)
  10362d4... preferences-window: Bind search model lazily (*)
  2557884... preferences-window: Fix search filter visible property (*)
  594eb98... Add Dutch translation (*)
  6e96ffc... examples: Bundle sassc in flatpak manifest (*)
  79474ee... Add sassc and libsass subprojects (*)
  616731f... Import Adwaita stylesheet (*)
  2625b9b... meson: Fix gresources indentation (*)
  367c8c7... readme: Remove outdated build instructions (*)
  acb6be8... stylesheet: Round window corners (*)
  838d242... stylesheet: Drop AdwWindow styles (*)
  4afb1e1... window-mixin: Drop the outline node (*)
  500a280... window-mixin: Drop the unified style class (*)
  3df37b8... window: Drop css node docs (*)
  a4c90bc... preferences-window: Make the search result margin adaptive (*)
  04c60ae... view-switcher-title: Fix dispose() (*)
  9517110... header-bar: Set focus funcs for the gizmos

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