ci(fix): build-args list type is actually a whitepsace delimited string list

Author: polarathene

.github/workflows/docker-3.2.yml

@@ -56,8 +56,7 @@ jobs:
           context: .
           file: Dockerfile.alpine
           platforms: linux/amd64,linux/386,linux/arm64,linux/arm/v7,linux/arm/v6,linux/ppc64le
-          build-args:
-            - GIT_BRANCH
+          build-args: GIT_BRANCH
           cache-from: type=gha, scope=${{ github.workflow }}
           cache-to: type=gha, scope=${{ github.workflow }}
           labels: ${{ steps.docker_meta.outputs.labels }}