When displaying the recently pushed branches banner, don't display
branches that have no common history with the default branch. These
branches are usually not meant to be merged, so the banner is just noise
in this case.
Refs: https://codeberg.org/forgejo/forgejo/pulls/2196
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
(cherry picked from commit e1fba517f4)
(cherry picked from commit 2d3c81d4f2)
(cherry picked from commit 624a61b3b8)