Merge commit '7335a43b6dac0e82c305ce4dec9db4da114c769e' into glitch-soc/merge-upstream

Conflicts:
- `app/helpers/application_helper.rb`:
  Upstream reworked how CSS classes for the document's body are computed.
  Slight conflict due to glitch-soc's different theming system.
  Updated as upstream did.

spec/requests/api/v1/statuses/sources_spec.rb

@@ -22,7 +22,7 @@ RSpec.describe 'Sources' do
         subject
 
         expect(response).to have_http_status(200)
-        expect(body_as_json).to match({
+        expect(response.parsed_body).to match({
           id: status.id.to_s,
           text: status.text,
           spoiler_text: status.spoiler_text,
@@ -52,7 +52,7 @@ RSpec.describe 'Sources' do
         subject
 
         expect(response).to have_http_status(200)
-        expect(body_as_json).to match({
+        expect(response.parsed_body).to match({
           id: status.id.to_s,
           text: status.text,
           spoiler_text: status.spoiler_text,