Merge commit 'f476d9dab2f5cca6ae44b95961df6b6557d66dab' into glitch-soc/merge-upstream

Conflicts:
- `lib/sanitize_ext/sanitize_config.rb`:
  Upstream enforced new code style rules, where we had different code.
  Applied the new code style rules.

spec/lib/activitypub/adapter_spec.rb

@@ -53,7 +53,7 @@ RSpec.describe ActivityPub::Adapter do
   describe '#serializable_hash' do
     subject { ActiveModelSerializers::SerializableResource.new(TestObject.new(foo: 'bar'), serializer: serializer_class, adapter: described_class).as_json }
 
-    let(:serializer_class) {}
+    let(:serializer_class) { nil }
 
     context 'when serializer defines no context' do
       let(:serializer_class) { TestWithBasicContextSerializer }