ci: fix release artifacts processing

Author: lklimek

.github/workflows/release-docker-image.yml

@@ -82,7 +82,7 @@ jobs:
       - name: Upload digest
         uses: actions/upload-artifact@v4
         with:
-          name: ${{ env.DIGEST_NAME }}
+          name: ${{ env.DIGEST_NAME }}-${{ matrix.platform }}
           path: ${{ env.DIGEST_DIR_PATH }}/*
           if-no-files-found: error
           retention-days: 1
@@ -93,10 +93,11 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Download digests
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
-          name: ${{ env.DIGEST_NAME }}
+          pattern: ${{ env.DIGEST_NAME }}*
           path: ${{ env.DIGEST_DIR_PATH }}
+          merge-multiple: true
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3