Merge branch 'master' into glitch-soc/merge-upstream

Conflicts:
	Gemfile

Solved conflicts by using upstream's line for posix-spawn

app/javascript/mastodon/locales/pl.json

@@ -287,7 +287,7 @@
   "upload_button.label": "Dodaj zawartość multimedialną",
   "upload_form.description": "Wprowadź opis dla niewidomych i niedowidzących",
   "upload_form.focus": "Przytnij",
-  "upload_form.undo": "Cofnij",
+  "upload_form.undo": "Usuń",
   "upload_progress.label": "Wysyłanie",
   "video.close": "Zamknij film",
   "video.exit_fullscreen": "Opuść tryb pełnoekranowy",