fix: update broken TODO link

Signed-off-by: Jakob Möller <[email protected]>

Author: jakobmoellerdev

pkg/applyset/tracker.go

@@ -51,7 +51,7 @@ type ApplyableObject struct {
 	ID string
 
 	// Lifecycle hints
-	// TODO(barney-s): need to exapnd on these: https://github.com/kubernetes-sigs/issues/542
+	// TODO(barney-s): need to exapnd on these: https://github.com/kubernetes-sigs/kro/issues/542
 	ExternalRef bool
 
 	// lastReadRevision is the revision of the object that was last read from the cluster.