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

Conflicts:
- `app/controllers/admin/base_controller.rb`:
  Minor conflict caused by glitch-soc's theming system.
- `app/javascript/mastodon/initial_state.js`:
  Minor conflict caused by glitch-soc making use of max_toot_chars.
- `app/models/form/admin_settings.rb`:
  Minor conflict caused by glitch-soc's theming system.
- `app/models/trends.rb`:
  Minor conflict caused by glitch-soc having more granular
  notification settings for trends.
- `app/views/admin/accounts/index.html.haml`:
  Minor conflict caused by glitch-soc's theming system.
- `app/views/admin/instances/show.html.haml`:
  Minor conflict caused by glitch-soc's theming system.
- `app/views/layouts/application.html.haml`:
  Minor conflict caused by glitch-soc's theming system.
- `app/views/settings/preferences/notifications/show.html.haml`:
  Minor conflict caused by glitch-soc having more granular
  notification settings for trends.
- `config/navigation.rb`:
  Minor conflict caused by glitch-soc having additional
  navigation items for the theming system while upstream
  slightly changed every line.

spec/controllers/admin/domain_blocks_controller_spec.rb

@@ -4,7 +4,7 @@ RSpec.describe Admin::DomainBlocksController, type: :controller do
   render_views
 
   before do
-    sign_in Fabricate(:user, admin: true), scope: :user
+    sign_in Fabricate(:user, role: UserRole.find_by(name: 'Admin')), scope: :user
   end
 
   describe 'GET #new' do