Add Helm v4.0.0-beta.1 support to CI and update version constants

Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>

.github/workflows/Makefile

@@ -1,4 +1,4 @@
-HELM_VERSION ?= v3.7.2
+HELM_VERSION ?= v4.0.0-beta.1
 KUSTOMIZE_VERSION ?= v5.4.3
 K8S_VERSION ?= v1.32.1
 MINIKUBE_VERSION ?= v1.31.1

.github/workflows/ci.yaml

@@ -86,6 +86,12 @@ jobs:
             plugin-secrets-version: 4.6.5
             plugin-diff-version: 3.12.5
             extra-helmfile-flags: '--enable-live-output'
+          # Test with Helm v4 beta
+          - helm-version: v4.0.0-beta.1
+            kustomize-version: v5.4.3
+            plugin-secrets-version: 4.6.5
+            plugin-diff-version: 3.12.5
+            extra-helmfile-flags: ''
     steps:
       - uses: actions/checkout@v5
       - uses: actions/setup-go@v6