Merge branch 'pl-rubocop-manual-todo-rspec-any-instance' into 'master'

Enable RSpec/AnyInstanceOf cop and move offenses to .rubocop_manual_todo.yml

See merge request gitlab-org/gitlab!49770

.rubocop.yml

@@ -440,9 +440,6 @@ Graphql/Descriptions:
     - 'app/graphql/**/*'
     - 'ee/app/graphql/**/*'
 
-RSpec/AnyInstanceOf:
-  Enabled: false
-
 # Cops for upgrade to gitlab-styles 3.1.0
 RSpec/ImplicitSubject:
   Enabled: false