[epiphany] (3 commits) Non-fast-forward update to branch wip/exalm/dark

[Alexander Mikhaylenko <alexm src gnome org>]

The branch 'wip/exalm/dark' 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:

  e329f86... shell: Opt into dark preference
  d1bc84c... Follow the system dark preference for reader mode

Commits added to the branch:

  c5933c8... ci: Switch scanbuild job to the gnome image
  98e87d7... shell: Opt into dark preference
  96413d0... Follow the system dark preference for reader mode