Fix build workflow

.forgejo/workflows/build.yaml

@@ -8,25 +8,30 @@ on:
 
 jobs:
   build:
-    runs-on: "docker"
+    runs-on: "docker://code.forgejo.org/oci/alpine:3.21"
 
     steps:
       - name: "Checkout"
         uses: "https://code.forgejo.org/actions/checkout@v4"
 
-      - name: "Setup Docker"
-        uses: "https://github.com/docker/setup-docker-action@v4"
+      - name: "Install Podman and Buildah"
+        run: "apk add podman buildah"
 
-      - name: "Login to the container registry"
-        uses: "https://github.com/docker/login-action@v3"
-        with:
-          registry: git.moritzruth.de
-          username: ${{ github.actor }}
-          password: ${{ github.token }}
-
-      - name: "Build and push"
-        uses: "https://github.com/docker/build-push-action@v6"
+      - name: "Build the container image"
+        id: "build-image"
+        uses: "https://github.com/redhat-actions/buildah-build@v2"
         with:
           file: "Containerfile"
           push: true
-          tags: "git.moritzruth.de/moritzruth/sscdc:${{ github.ref_name }}"
+          image: "git.moritzruth.de/moritzruth/sscdc"
+          tags: "${{ github.ref_name }}"
+          containerfiles: "./Containerfile"
+
+      - name: "Push the container image to the registry"
+        uses: "https://github.com/redhat-actions/push-to-registry@v2"
+        with:
+          image: ${{ steps.build-image.outputs.image }}
+          tags: ${{ steps.build-image.outputs.tags }}
+          registry: git.moritzruth.de
+          username: ${{ github.actor }}
+          password: ${{ github.token }}