Update docker/build-push-action digest to 6003d32 (#133)

Author: renovate[bot]

.github/workflows/publish_server.yml

@@ -44,7 +44,7 @@ jobs:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
 
       - name: Build and push backend Docker image
-        uses: docker/build-push-action@729f7f49266dec5e72fe7339273d3f7e65abacd7
+        uses: docker/build-push-action@6003d3266a923de06063d23a19bd1c719af997c0
         with:
           context: ./server/
           file: ./server/Dockerfile