[gtk] (4 commits) Non-fast-forward update to branch mcatanzaro/unparent

[Michael Catanzaro <mcatanzaro src gnome org>]

The branch 'mcatanzaro/unparent' 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:

  750b718... Remove incorrect unparenting guidance from migration guide

Commits added to the branch:

  87e0a28... ci: Specify `only` for other jobs (*)
  195b98f... ci: Only run macOS job on upstream branches (*)
  e930a20... Merge branch 'ebassi/ci-only' into 'master' (*)
  5969259... Remove incorrect unparenting guidance from migration guide

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