Follow-up from "Update CAPI to v1.8.3, CAPBPR RKE2 bootstrap provider to 0.7.1"

The following discussion from !2961 (merged) should be addressed:

• @feleouet started a discussion: (+2 comments)

  Wouldn't it be safer to add a check to ensure that cluster.x-k8s.io/cluster-name has been set? this could be racy and lead to unpredictable results if the has not yet been set by capi controller.