[gimp] (4 commits) Non-fast-forward update to branch wip/Jehan/revert-json-c-CI

[Jehan <jehanp src gnome org>]

The branch 'wip/Jehan/revert-json-c-CI' 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:

  2a879e4... Revert "build: fix json-c cross-build for Windows."

Commits added to the branch:

  7a4254d... m4macros: update ax_gcc_func_attribute.m4 to serial 12 (*)
  a928452... Fix typos (*)
  8d5afa7... issue 4669 (*)
  bed95eb... Revert "build: fix json-c cross-build for Windows."

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