Update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/deploy.yaml

@@ -19,7 +19,7 @@ jobs:
           password: ${{ secrets.DOCKER_REGISTRY_PASSWORD }}
       - name: Build and push
         id: docker_build
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           push: true
           tags: postmodern.alexdaniel.org/oppejoud-backend:${{ github.sha }} ${{ github.ref == 'refs/heads/main' && ', postmodern.alexdaniel.org/oppejoud-backend:latest' || '' }}