chore(deps): update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/push-pr-lint.yaml

@@ -38,7 +38,7 @@ jobs:
 
       - name: Build Alloy Docker image - no push
         id: dockerbuild-alloy
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: false