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

Conflicts:
- `README.md`:
  Discarded upstream changes: we have our own README
- `app/controllers/follower_accounts_controller.rb`:
  Port upstream's minor refactoring

spec/models/account_spec.rb

@@ -160,7 +160,7 @@ RSpec.describe Account, type: :model do
         expect(account.avatar_remote_url).to eq 'https://remote.test/invalid_avatar'
         expect(account.header_remote_url).to eq expectation.header_remote_url
         expect(account.avatar_file_name).to  eq nil
-        expect(account.header_file_name).to  eq nil
+        expect(account.header_file_name).to  eq expectation.header_file_name
       end
     end
   end
@@ -658,6 +658,12 @@ RSpec.describe Account, type: :model do
     end
   end
 
+  describe '.requested_by_map' do
+    it 'returns an hash' do
+      expect(Account.requested_by_map([], 1)).to be_a Hash
+    end
+  end
+
   describe 'MENTION_RE' do
     subject { Account::MENTION_RE }