rewrite release workflow

Author: eksrha

.github/workflows/release.yaml

@@ -4,9 +4,9 @@ env:
   IMAGE_PLATFORMS: linux/386,linux/amd64,linux/arm64,linux/arm/v7,linux/ppc64le
 
 on:
-  pull_request:
-    branches-ignore:
-      - "docu/**"
+  push:
+    branches:
+      - "maim"
     paths:
       - "docker-image/**"
       - "helm/**"