[gimp] (4 commits) Non-fast-forward update to branch nielsdg/devel-docs-porting-guide

[Jehan <jehanp src gnome org>]

The branch 'nielsdg/devel-docs-porting-guide' 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:

  9e48c20... devel-docs: Render GIMP3 porting guide in gi-docgen

Commits added to the branch:

  6acb5fd... configure, meson: bump libjxl dependency to 0.6.1 (*)
  f4c67d8... Update German translation (*)
  640bc9b... build: update gi-docgen feature setting in flatpak (*)
  ec38965... devel-docs: Render GIMP3 porting guide in gi-docgen

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