fix(actions): run review-triggered workflows on the pull request head (#40099)

Runs triggered by pull request reviews took their ref and commit from
the review's `commit_id` instead of the pull request. They now use the
pull request head like other pull request events, and their commit
status is set on the commit that ran.

tests/integration/actions_trigger_test.go

@@ -1373,11 +1373,12 @@ jobs:
 		assert.NoError(t, err)
 		defer gitRepo.Close()
 
-		_, _, err = pull_service.SubmitReview(t.Context(), user4, gitRepo, pullIssue, issues_model.ReviewTypeApprove, "lgtm", sha, nil)
+		_, _, err = pull_service.SubmitReview(t.Context(), user4, gitRepo, pullIssue, issues_model.ReviewTypeApprove, "lgtm", addWorkflow.Commit.SHA, nil)
 		assert.NoError(t, err)
 
 		// verify that a commit status was created for the review event
 		waitCommitStatusAndInsertFakeStatus(t, repo, sha)
+		assert.Equal(t, sha, unittest.AssertExistsAndLoadBean(t, &actions_model.ActionRun{RepoID: repo.ID}).CommitSHA)
 	})
 }