Merge commit '0ad2413b35287958f59073a5b63aecc659a64d98' into glitch-soc/merge-upstream

Conflicts:
- `app/javascript/styles/mastodon/forms.scss`:
  Conflict because we ran eslint autofix on upstream files.
- `config/initializers/content_security_policy.rb`:
  Code style changes but we have a different version.
  Kept our version.
- `streaming/index.js`:
  Upstream fixed a typo close to glitch-soc-only code.
  Applied upstream's changes.

spec/controllers/auth/registrations_controller_spec.rb

@@ -104,9 +104,9 @@ RSpec.describe Auth::RegistrationsController, type: :controller do
     end
 
     around do |example|
-      current_locale = I18n.locale
-      example.run
-      I18n.locale = current_locale
+      I18n.with_locale(I18n.locale) do
+        example.run
+      end
     end
 
     before { request.env['devise.mapping'] = Devise.mappings[:user] }