fix: platforms value in gh action

Signed-off-by: Hung-Han (Henry) Chen <[email protected]>

Author: chenhunghan

.github/workflows/build_images.yaml

@@ -88,10 +88,7 @@ jobs:
         with:
           context: .
           file: ./Dockerfile
-          platforms:
-            - linux/amd64
-            - linux/arm64
-            - linux/arm
+          platforms: linux/amd64,linux/arm64,linux/arm
           push: true
           build-args: |
             "KEYCLOAK_VERSION=${{ matrix.keycloak_version }}"