Ignore review comment when ref commit is missed (#16905) (#16919)

backport #16905

modules/migrations/gitea_uploader.go

@@ -808,7 +808,8 @@ func (g *GiteaLocalUploader) CreateReviews(reviews ...*base.Review) error {
 			}
 			headCommitID, err := g.gitRepo.GetRefCommitID(pr.GetGitRefName())
 			if err != nil {
-				return fmt.Errorf("GetRefCommitID[%s]: %v", pr.GetGitRefName(), err)
+				log.Warn("GetRefCommitID[%s]: %v, the review comment will be ignored", pr.GetGitRefName(), err)
+				continue
 			}
 
 			var patch string