these were duplicates. In GNOME 46-beta this dialog seems to be
in 'light mode' at least some of the time, so we'll keep the
'light mode' gnome_allow needle we added for Snapshot but
rename it and change its tags. We'll wipe the 'dark mode'
gnome_allow because it should be just the same as the existing
grant_access needle. The two tests that used gnome_allow are
changed to use grant_access.
Signed-off-by: Adam Williamson <awilliam@redhat.com>