Batch-load related data in actions run, job, and task API endpoints (#37032)

Avoid per-item DB queries in ListRuns, ListJobs, and ListActionTasks by
batch-loading trigger users, repositories, and task attributes before
the conversion loop. Remove ReferencesGitRepo from the /actions route
group since no task/run endpoints use it.

Added tests for these endpoints as well.

---------

Signed-off-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>

services/actions/notifier.go

@@ -815,7 +815,8 @@ func (n *actionsNotifier) WorkflowRunStatusUpdate(ctx context.Context, repo *rep
 		log.Error("GetActionWorkflow: %v", err)
 		return
 	}
-	convertedRun, err := convert.ToActionWorkflowRun(ctx, repo, run, nil)
+	run.Repo = repo
+	convertedRun, err := convert.ToActionWorkflowRun(ctx, run, nil)
 	if err != nil {
 		log.Error("ToActionWorkflowRun: %v", err)
 		return