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

Conflicts:
- `.github/dependabot.yml`:
  Updated upstream, removed in glitch-soc to disable noise.
  Kept removed.
- `CODE_OF_CONDUCT.md`:
  Upstream updated to a new version of the covenant, but I have not read it
  yet, so kept unchanged.
- `Gemfile.lock`:
  Not a real conflict, one upstream dependency updated textually too close to
  the glitch-soc only `hcaptcha` dependency.
  Applied upstream changes.
- `app/controllers/admin/base_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `app/controllers/application_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `app/controllers/disputes/base_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `app/controllers/relationships_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `app/controllers/statuses_cleanup_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `app/helpers/application_helper.rb`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `app/javascript/mastodon/features/compose/components/compose_form.jsx`:
  Upstream added a highlight animation for onboarding, while we changed the
  max character limit.
  Applied our local changes on top of upstream's new version.
- `app/views/layouts/application.html.haml`:
  Minor conflict due to glitch-soc's theming system.
  Applied upstream changes.
- `stylelint.config.js`:
  Upstream added ignore paths, glitch-soc had extra ignore paths.
  Added the same paths as upstream.

app/helpers/application_helper.rb

@@ -155,20 +155,8 @@ module ApplicationHelper
     tag(:meta, content: content, property: property)
   end
 
-  def react_component(name, props = {}, &block)
-    if block.nil?
-      content_tag(:div, nil, data: { component: name.to_s.camelcase, props: Oj.dump(props) })
-    else
-      content_tag(:div, data: { component: name.to_s.camelcase, props: Oj.dump(props) }, &block)
-    end
-  end
-
-  def react_admin_component(name, props = {})
-    content_tag(:div, nil, data: { 'admin-component': name.to_s.camelcase, props: Oj.dump({ locale: I18n.locale }.merge(props)) })
-  end
-
   def body_classes
-    output = (@body_classes || '').split
+    output = body_class_string.split
     output << "flavour-#{current_flavour.parameterize}"
     output << "skin-#{current_skin.parameterize}"
     output << 'system-font' if current_account&.user&.setting_system_font_ui