Extend the batch comments test to the MR resolve button fix
gitlab-org/gitlab#32157 (closed) fixed a bug in which the resolve button did not appear in an MR discussion if there was a system note.
Although it's now covered by a unit test, it wouldn't hurt to also cover it with an E2E test given that the test qa/specs/features/ee/browser_ui/3_create/merge_request/add_batch_comments_in_merge_request_spec.rb
sets up most of the steps required already. It only needs to:
- add a system note to an unresolved discussion (the test already creates an unresolved discussion)
- try to resolve the discussion
The system note could be added by pushing a commit that changes the line on which the discussion was started.