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

Conflicts:
- `app/javascript/mastodon/features/compose/components/compose_form.js`:
  Conflict caused because of minor code style change upstream, while glitch-soc
  has different code for handling variable maximum chars.
  Ported the change.
- `app/serializers/initial_state_serializer.rb`:
  Conflict because glitch-soc had two extra attributes where upstream added
  one.
  Added upstream's attribute.

app/javascript/mastodon/initial_state.js

@@ -28,5 +28,6 @@ export const showTrends = getMeta('trends');
 export const title = getMeta('title');
 export const cropImages = getMeta('crop_images');
 export const disableSwiping = getMeta('disable_swiping');
+export const languages = initialState && initialState.languages;
 
 export default initialState;