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/policies/status_policy_spec.rb

@@ -6,7 +6,7 @@ require 'pundit/rspec'
 RSpec.describe StatusPolicy, type: :model do
   subject { described_class }
 
-  let(:admin) { Fabricate(:user, admin: true) }
+  let(:admin) { Fabricate(:user, role: UserRole.find_by(name: 'Admin')) }
   let(:alice) { Fabricate(:account, username: 'alice') }
   let(:bob) { Fabricate(:account, username: 'bob') }
   let(:status) { Fabricate(:status, account: alice) }