fix: Ensure metallb speaker runs on tainted nodepools

Author: jimmidyson

charts/cluster-api-runtime-extensions-nutanix/addons/serviceloadbalancer/metallb/values-template.yaml

@@ -15,8 +15,7 @@ speaker:
       tag: 9.1.3
   priorityClassName: system-cluster-critical
   tolerations:
-    - key: node-role.kubernetes.io/control-plane
-      effect: NoSchedule
+    - effect: NoSchedule
       operator: Exists
     - key: CriticalAddonsOnly
       operator: Exists