[libadwaita] (32 commits) Non-fast-forward update to branch wip/exalm/borderless

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/borderless' 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:

  1354c22... Revert "stylesheet: Use darker headerbar for focused window
  dcd374b... Revert "Revert "stylesheet: Restore a backdrop state for he
  43e9287... Revert "Revert "stylesheet: Add back a backdrop state for A
  db8e0d9... Add AdwSplitButton
  94f191f... stylesheet: Use toolbar style for header bars and action ba
  92c3f3b... stylesheet: Reset toolbar styles for popovers
  c13b91a... stylesheet: Make GtkWindowControls buttons filled
  94f1fd6... stylesheet: Make image buttons square
  43c5d87... example

Commits added to the branch:

  1d5340b... avatar: Fix memory leaks (*)
  2c81acd... demo-window: Fix a memory leak (*)
  8555174... stylesheet: Fix slider for scale.marks-before.marks-after (*)
  d67535c... tests: add test for model correctness (*)
  f6302c0... tab-view: delay notify::selected-page until after setting (*)
  4c8d07b... doc: Add the alpha to alpha migration guide (*)
  f5932ab... Release 1.0.0-alpha.2 (*)
  a236e25... avatar: Use auto cleanups for Cairo types (*)
  c858375... icons: Update adw-expander-arrow-symbolic (*)
  959f434... demo: Update icons (*)
  8eae01f... squeezer: Reduce the scope of some variables (*)
  7265a43... squeezer: Typo fix (*)
  d459e69... squeezer: Add the allow-none property (*)
  1ee626b... demo: Quick hack to show how it works (*)
  8c79ff3... Revert "demo: Quick hack to show how it works" (*)
  11effb6... squeezer: Fix tests (*)
  a1f46b8... Revert "stylesheet: Use darker headerbar for focused window
  f880bf3... Revert "Revert "stylesheet: Restore a backdrop state for he
  e0a16eb... Revert "Revert "stylesheet: Add back a backdrop state for A
  c0a3ef6... Add AdwSplitButton
  a95ecdb... stylesheet: Use toolbar style for header bars and action ba
  2e936a7... stylesheet: Reset toolbar styles for popovers
  081e036... stylesheet: Make GtkWindowControls buttons filled
  6601d98... stylesheet: Make image buttons square
  5191a59... example
  6ba6b30... stylesheet: Drop an unused variable
  ff2a949... stylesheet: Remove alt border color
  58ec9cf... stylesheet: Stop using $borders_color for overshoot
  70cee88... stylesheet: Replace solid-csd border with an inset shadow
  12ede36... a
  a221445... stylesheet: Make sure header bar borders have contrast
  dd4c74d... Padding fixes

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