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

Conflicts:
- `.github/workflows/build-image.yml`:
  Fix erroneous deletion in a previous merge.
- `Gemfile`:
  Conflict caused by glitch-soc-only hCaptcha dependency
- `app/controllers/auth/sessions_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
- `app/controllers/filters_controller.rb`:
  Minor conflict due to glitch-soc's theming system.
- `app/serializers/rest/status_serializer.rb`:
  Minor conflict due to glitch-soc having an extra `local_only` property

app/lib/activitypub/parser/media_attachment_parser.rb

@@ -50,7 +50,7 @@ class ActivityPub::Parser::MediaAttachmentParser
     components = begin
       blurhash = @json['blurhash']
 
-      if blurhash.present? && /^[\w#$%*+-.:;=?@\[\]^{|}~]+$/.match?(blurhash)
+      if blurhash.present? && /^[\w#$%*+,-.:;=?@\[\]^{|}~]+$/.match?(blurhash)
         Blurhash.components(blurhash)
       end
     end