[libadwaita] (6 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:

  7a30a7b... stylesheet: Move header bar padding into an internal box

Commits added to the branch:

  b9b7b87... stylesheet: Remove 2 unused colors (*)
  8fc8eed... stylesheet: Unify error, warning and destructive colors (*)
  2bf0eb3... stylesheet: Remove separate variables for flat colored butt (*)
  7ead2f9... stylesheet: Use transparency for infobar hover/active state (*)
  8fa8a53... stylesheet: Redo infobars (*)
  fd6203c... stylesheet: Move header bar padding into an internal box

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