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

Conflicts:
- `app/javascript/mastodon/locales/ja.json`:
  Upstream change too close to a glitch-soc-specific string.
  The glitch-soc-specific string should not have been in this file, so it
  has been moved to `app/javascript/flavours/glitch/locales/ja.js`.
- `app/javascript/packs/public.js`:
  Upstream refactored a part, that as usual is split and duplicated in various
  pack files. Updated those pack files accordingly.
- `app/views/layouts/application.html.haml`:
  Upstream fixed custom.css path in a different way than we did, went with
  upstream's change.

app/validators/import_validator.rb

@@ -26,6 +26,8 @@ class ImportValidator < ActiveModel::Validator
     when 'following'
       validate_following_import(import, row_count)
     end
+  rescue CSV::MalformedCSVError
+    import.errors.add(:data, :malformed)
   end
 
   private