chore(workflow): use metallb official charts

Author: duanhongyi

_scripts/generate_cache.sh

@@ -13,15 +13,15 @@ trap clean_before_exit EXIT
 cd $tmp
 
 helm repo add cilium https://helm.cilium.io/
-helm repo add bitnami https://charts.bitnami.com/bitnami
+helm repo add metallb https://metallb.github.io/metallb
 helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
 helm repo add longhorn https://charts.longhorn.io
 helm repo add jetstack https://charts.jetstack.io
 helm repo add svc-cat https://kubernetes-sigs.github.io/service-catalog
 helm repo update
 
 helm fetch cilium/cilium
-helm fetch bitnami/metallb
+helm fetch metallb/metallb
 helm fetch ingress-nginx/ingress-nginx
 helm fetch longhorn/longhorn
 helm fetch jetstack/cert-manager