feature: namespace deletion member service account

The registration service uses the member service account to be able to
interact with the member clusters. In order to be able to delete the
user namespaces to trigger a reconciliation from the NSTemplateSet
controller, we need the service account to have the "delete" permission
too.

SANDBOX-1067

Author: MikelAlejoBR

testsupport/wait/member.go

@@ -2657,7 +2657,7 @@ func (a *MemberAwaitility) WaitForToolchainClusterResources(t *testing.T) {
 		{
 			APIGroups: []string{""},
 			Resources: []string{"namespaces"},
-			Verbs:     []string{"get", "list", "watch"},
+			Verbs:     []string{"delete", "get", "list", "watch"},
 		},
 		{
 			APIGroups: []string{""},