[pitivi] (15 commits) Non-fast-forward update to branch thiblahute/sdk3.30

[Thibault Saunier <tsaunier src gnome org>]

The branch 'thiblahute/sdk3.30' 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:

  9073434... flatpak: Allow '/' in branch names
  11d3348... ci: docker: Build against GNOME 3.30
  ddb83d5... build: Update flatpak SDK and deps
  79c9b3e... ci: Add a target to update our flatpak repository
  8101e67... WIP

Commits added to the branch:

  1487bcf... docs: Fix instructions for installing the flatpak Runtime S (*)
  d8a35fa... docs: Update testing (*)
  1d18ca0... docs: Update past GSoCs (*)
  47131b3... docs: Update the top page (*)
  9ce981e... prefs: Fix g_object_set_is_valid_property warning (*)
  fb0b65b... medialibrary: Show unsupported assets (*)
  7f5a608... timeline: Fix touchpad scrolling (*)
  d91c128... viewer: Show resize status (*)
  371581a... viewer: Snap the viewer size (*)
  1cdd915... Update German translation (*)
  d516d2b... flatpak: Allow '/' in branch names
  449d77f... ci: docker: Build against GNOME 3.30
  b599bea... build: Update flatpak SDK and deps
  55d19e3... ci: Add a target to update our flatpak repository
  c15c0cb... WIP

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