[libadwaita] (6 commits) Non-fast-forward update to branch wip/cdavis/fold-threshold-policy

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/cdavis/fold-threshold-policy' 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:

  08c3c3c... Add AdwFoldThresholdPolicy
  28782a7... leaflet: Add fold-threshold-policy property
  7509fd3... flap: Add fold-threshold-policy-property

Commits added to the branch:

  97f8aba... Revert "stylesheet: Add back a backdrop state for AdwTabBar (*)
  284af49... Revert "stylesheet: Restore a backdrop state for header bar (*)
  9119565... stylesheet: Use darker headerbar for focused windows (*)
  0c24178... Add AdwFoldThresholdPolicy
  965242d... leaflet: Add fold-threshold-policy property
  a527ad4... flap: Add fold-threshold-policy-property

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