build: Rebase container image

.gitea/workflows/actions.yaml

@@ -86,9 +86,6 @@ jobs:
       - name: Build & push container image
         uses: docker/build-push-action@v5
         with:
-          build-args: |
-            REPO_USERNAME=${{ secrets.REPO_USERNAME }}
-            REPO_PASSWORD=${{ secrets.REPO_PASSWORD }}
           context: .
           tags: code.spamasaurus.com/djpbessems/json-server:${{ needs.semrel_dryrun.outputs.version }}
           provenance: false
@@ -103,7 +100,7 @@ jobs:
     name: Helm chart
     runs-on: dind
     needs: semrel_dryrun
-    container: ghcr.io/catthehacker/ubuntu:act-latest
+    container: alpine/helm
     steps:
       - name: Check out repository code
         uses: actions/checkout@v4