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

Conflicts:
- `.prettierignore`:
  Upstream added a line at the end of the file, while glitch-soc had its own
  extra lines.
  Took upstream's change.
- `CONTRIBUTING.md`:
  We have our custom CONTRIBUTING.md quoting upstream. Upstream made changes.
  Ported upstream changes.
- `app/controllers/application_controller.rb`:
  Upstream made code style changes in a method that is entirely replaced
  in glitch-soc.
  Ignored the change.
- `app/models/account.rb`:
  Code style changes textually close to glitch-soc-specific changes.
  Ported upstream changes.
- `lib/sanitize_ext/sanitize_config.rb`:
  Upstream code style changes.
  Ignored them.

spec/controllers/application_controller_spec.rb

@@ -28,7 +28,7 @@ describe ApplicationController, type: :controller do
     end
 
     it 'renders template for http' do
-      is_expected.to render_template("errors/#{code}", layout: 'error')
+      expect(subject).to render_template("errors/#{code}", layout: 'error')
     end
   end
 
@@ -57,19 +57,19 @@ describe ApplicationController, type: :controller do
   describe 'helper_method :single_user_mode?' do
     it 'returns false if it is in single_user_mode but there is no account' do
       allow(Rails.configuration.x).to receive(:single_user_mode).and_return(true)
-      expect(controller.view_context.single_user_mode?).to eq false
+      expect(controller.view_context.single_user_mode?).to be false
     end
 
     it 'returns false if there is an account but it is not in single_user_mode' do
       allow(Rails.configuration.x).to receive(:single_user_mode).and_return(false)
       Fabricate(:account)
-      expect(controller.view_context.single_user_mode?).to eq false
+      expect(controller.view_context.single_user_mode?).to be false
     end
 
     it 'returns true if it is in single_user_mode and there is an account' do
       allow(Rails.configuration.x).to receive(:single_user_mode).and_return(true)
       Fabricate(:account)
-      expect(controller.view_context.single_user_mode?).to eq true
+      expect(controller.view_context.single_user_mode?).to be true
     end
   end