Adjust workflow to run with artifacts v4

Signed-off-by: Christian König <ckoenig@posteo.de>

.github/workflows/build-and-publish.yml

@@ -23,9 +23,21 @@ jobs:
           - registry: dockerhub
             platform: linux/riscv64
             alpine_version: edge
+            platform_dir: linux-riscv64
           - registry: ghcr
             platform: linux/riscv64
             alpine_version: edge
+            platform_dir: linux-riscv64
+          - platform: linux/amd64
+            platform_dir: linux-amd64
+          - platform: linux/386
+            platform_dir: linux-386
+          - platform: linux/arm/v6
+            platform_dir: linux-arm-v6
+          - platform: linux/arm/v7
+            platform_dir: linux-arm-v7
+          - platform: linux/arm64
+            platform_dir: linux-arm64
     steps:
       - name: Checkout Repo
         uses: actions/checkout@v4
@@ -79,7 +91,7 @@ jobs:
       - name: Upload digest
         uses: actions/upload-artifact@v4
         with:
-          name: digests
+          name: ${{ matrix.platform_dir}}
           path: /tmp/digests/*
           if-no-files-found: error
           retention-days: 1
@@ -101,9 +113,14 @@ jobs:
 
       - name: Download digests
         uses: actions/download-artifact@v4
+        id: download
         with:
-          name: digests
-          path: /tmp/digests
+          path: /tmp/download
+      
+      - name: Copy all artifacts from sub-directories to /tmp/digests
+        run: |
+          mkdir /tmp/digests
+          cp ${{steps.download.outputs.download-path}}/**/* /tmp/digests
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3