chore: simplify build scripts for kubectl apply when handling kustomization resources

Signed-off-by: joengjyu <joengjyu@gmail.com>

charts/karmada/templates/post-install-job.yaml

@@ -89,7 +89,7 @@ spec:
         - |
           bash <<'EOF'
           set -ex
-          kubectl kustomize /crds | kubectl apply --kubeconfig /etc/kubeconfig -f -
+          kubectl apply -k /crds --kubeconfig /etc/kubeconfig
           kubectl apply -f /static-resources --kubeconfig /etc/kubeconfig
           EOF
         volumeMounts:

docs/upgrading/README.md

@@ -62,7 +62,7 @@ kubectl kustomize ./charts/karmada/_crds
 ```
 Or, you can apply to `karmada-apiserver` by:
 ```bash
-kubectl kustomize ./charts/karmada/_crds | kubectl apply -f -
+kubectl apply -k ./charts/karmada/_crds
 ```
 
 ### Upgrading Components

hack/deploy-karmada.sh

@@ -109,7 +109,7 @@ function installCRDs() {
 
     kubectl apply -f "${REPO_ROOT}/artifacts/deploy/namespace.yaml"
 
-    kubectl kustomize "${crd_path}"/_crds | kubectl apply -f -
+    kubectl apply -k "${crd_path}"/_crds
 }
 
 # Use x.x.x.6 IP address, which is the same CIDR with the node address of the Kind cluster,