Remove dependency on gnome-online-miners
gnome-online-miners was removed from core last year because it didn't port to tracker 3 (reference) and now I've just had it archived (reference) since (a) it still depends on tracker 2, (b) it's unmaintained, and (c) the only app that depends on it is Photos.
We should either copy the portions of gnome-online-miners that Photos uses into Photos, or else remove these features. fyi: @aday @bilelmoussaoui
(Previously, Documents and Books depended on it too, but those have both been archived as well. We actually did not know until recently that Photos used gnome-online-miners because there was no dependency declared in gnome-photos.bst, so we just assumed Documents and Books were the only consumers. Probably would not have removed it from core so casually had we known, but that happened over a year ago so no point in revisiting it now.)