fix(act): split image build into multiple jobs

.forgejo/workflows/act_runtime.yaml

@@ -14,13 +14,16 @@ env:
   LLVM_VERSIONS: '{"24.04": "19", "22.04": "15"}'
 
 jobs:
-  build_images:
+  build:
     strategy:
       matrix:
-        base_tage:
+        arch:
+          - arm64
+          - amd64
+        base_tag:
           - "22.04"
           - "24.04"
-    runs-on: ubuntu-latest-amd64
+    runs-on: ubuntu-latest-${{ matrix.arch }}
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -39,8 +42,31 @@ jobs:
         with:
           context: "./act_runtime"
           push: true
-          platforms: linux/amd64,linux/arm64
-          tags: code.icb4dc0.de/infrastructure/images/act_runtime:${{ matrix.base_tage }}
+          tags: code.icb4dc0.de/infrastructure/images/act_runtime:${{ matrix.base_tag }}-${{ matrix.arch }}
           build-args: |
-            BASE_IMAGE=ubuntu:${{ matrix.base_tage }}
-            LLVM_VERSION=${{ fromJSON(env.LLVM_VERSIONS)[matrix.base_tage] }}
+            BASE_IMAGE=ubuntu:${{ matrix.base_tag }}
+            LLVM_VERSION=${{ fromJSON(env.LLVM_VERSIONS)[matrix.base_tag] }}
+
+  manifest:
+    strategy:
+      matrix:
+        base_tag:
+          - "22.04"
+          - "24.04"
+    runs-on: ubuntu-latest
+    needs:
+      - build
+    steps:
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          registry: code.icb4dc0.de
+          username: prskr
+          password: ${{ secrets.CONTAINER_REGISTRY_TOKEN }}
+
+      - name: Create manifest
+        run: |
+          docker manifest create code.icb4dc0.de/infrastructure/images/act_runtime:${{ matrix.base_tag }} \
+              --amend code.icb4dc0.de/infrastructure/images/act_runtime:${{ matrix.base_tag }}-arm64 \
+              --amend code.icb4dc0.de/infrastructure/images/act_runtime:${{ matrix.base_tag }}-amd64
+          docker manifest push code.icb4dc0.de/infrastructure/images/act_runtime:${{ matrix.base_tag }}