[gdk-pixbuf] (9 commits) ...Merge branch 'ebassi/for-master' into 'master'

[Emmanuele Bassi <ebassi src gnome org>]

Summary of changes:

  192e948... Use g_filename_display_name() with files inside GError mess (*)
  d9b59fb... bmp: Use g_set_error_literal() (*)
  9284c56... build: Fix libjpeg checks (*)
  c44312e... Update the checksum for the libjpeg source archive (*)
  676533c... ci: Specify 0.56.2 as the installed Meson version (*)
  7583d07... build: Use old syntax for fallback dependencies (*)
  e7b6681... build: Don't do function checks for subprojects (*)
  993e75a... build: Reorganise the libjpeg checks (*)
  0cc1b8b... Merge branch 'ebassi/for-master' into 'master'

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