Remove the delete local manifest when remote doesn't exist (#20597)

Previous impl it calls c.local.DeleteManifest(remoteRepo, art.Tag), because the remoteRepo is incorrect repository and it always delete nothing, to keep consistency with the previous version and code clarity, remove this go routine

Signed-off-by: stonezdj <stone.zhang@broadcom.com>

src/controller/proxy/controller.go

@@ -172,9 +172,6 @@ func (c *controller) UseLocalManifest(ctx context.Context, art lib.ArtifactInfo,
 		return false, nil, err
 	}
 	if !exist || desc == nil {
-		go func() {
-			c.local.DeleteManifest(remoteRepo, art.Tag)
-		}()
 		return false, nil, errors.NotFoundError(fmt.Errorf("repo %v, tag %v not found", art.Repository, art.Tag))
 	}
 
@@ -220,11 +217,6 @@ func (c *controller) ProxyManifest(ctx context.Context, art lib.ArtifactInfo, re
 	ref := getReference(art)
 	man, dig, err := remote.Manifest(remoteRepo, ref)
 	if err != nil {
-		if errors.IsNotFoundErr(err) {
-			go func() {
-				c.local.DeleteManifest(remoteRepo, art.Tag)
-			}()
-		}
 		return man, err
 	}
 	ct, _, err := man.Payload()