Merge commit 'fe04291af46d7cb9d3439fa73739b2ffb2b53d72' into glitch-soc/merge-upstream

Conflicts:
- `spec/lib/sanitize/config_spec.rb`:
  Upstream rewrote top-level `describe` calls to `RSpec.describe`, and
  glitch-soc had differences in the first few tests because of the wider
  subset of HTML it accepts.
  Changed `describe` to `RSpec.describe` as upstream did, keeping
  glitch-soc's tests.

spec/controllers/application_controller_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe ApplicationController do
+RSpec.describe ApplicationController do
   controller do
     def success
       head 200