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>

models/repo/repo.go

@@ -376,8 +376,9 @@ func (repo *Repository) CommitLink(commitID string) (result string) {
 }
 
 // APIURL returns the repository API URL
-func (repo *Repository) APIURL() string {
-	return setting.AppURL + "api/v1/repos/" + url.PathEscape(repo.OwnerName) + "/" + url.PathEscape(repo.Name)
+func (repo *Repository) APIURL(ctxOpt ...context.Context) string {
+	ctx := util.OptionalArg(ctxOpt, context.TODO())
+	return httplib.MakeAbsoluteURL(ctx, setting.AppSubURL+"/api/v1/repos/"+url.PathEscape(repo.OwnerName)+"/"+url.PathEscape(repo.Name))
 }
 
 // GetCommitsCountCacheKey returns cache key used for commits count caching.