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

Conflicts:
- Gemfile
- app/controllers/api/v1/search_controller.rb
  Conflict because we changed the number of default results to be
  configurable
- app/lib/settings/scoped_settings.rb
  Addition of a new “noindex” site-wide setting,
  conflict due to our change of the two other site-wide settings
  (default flavour and skin instead of theme)
- spec/controllers/application_controller_spec.rb
  Addition of a new “noindex” site-wide setting,
  conflict due to our change of the two other site-wide settings
  (default flavour and skin instead of theme)

app/models/form/admin_settings.rb

@@ -38,6 +38,7 @@ class Form::AdminSettings
     trends
     show_domain_blocks
     show_domain_blocks_rationale
+    noindex
   ).freeze
 
   BOOLEAN_KEYS = %i(
@@ -55,6 +56,7 @@ class Form::AdminSettings
     show_replies_in_public_timelines
     spam_check_enabled
     trends
+    noindex
   ).freeze
 
   UPLOAD_KEYS = %i(