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

Conflicts:
- `app/services/remove_status_service.rb`:
  Conflict caused by us having a distinc Direct timeline.
  Ported upstream changes.
- `app/javascript/mastodon/features/compose/components/compose_form.js`:
  Conflict between glitch-soc's variable character limit and upstream
  refactoring that part of the code.
  Ported upstream changes.

Gemfile

@@ -44,6 +44,7 @@ gem 'net-ldap', '~> 0.16'
 gem 'omniauth-cas', '~> 2.0'
 gem 'omniauth-saml', '~> 1.10'
 gem 'omniauth', '~> 1.9'
+gem 'omniauth-rails_csrf_protection', '~> 0.1'
 
 gem 'color_diff', '~> 0.1'
 gem 'discard', '~> 1.2'