ci: patch vllm metrics route discovery

Signed-off-by: Sumanth Kamenani <skamenan@redhat.com>

Author: skamenan7

.github/actions/setup-vllm-gpu/action.yml

@@ -95,6 +95,31 @@ runs:
         python -c "import torch; print(f'CUDA device count: {torch.cuda.device_count()}')"
         vllm --version
 
+    - name: Patch vLLM metrics route discovery
+      shell: bash
+      run: |
+        source /tmp/vllm-env/bin/activate
+
+        python - <<'PY'
+        from __future__ import annotations
+
+        from pathlib import Path
+        import prometheus_fastapi_instrumentator.routing as routing
+
+        routing_path = Path(routing.__file__)
+        source = routing_path.read_text()
+        old = "route_name = route.path"
+        new = (
+            "route_name = getattr(route, 'path', None)\n"
+            "            if route_name is None:\n"
+            "                continue"
+        )
+        if old not in source:
+            raise SystemExit(f"Expected route.path assignment not found in {routing_path}")
+        routing_path.write_text(source.replace(old, new, 1))
+        print(f"Patched {routing_path}")
+        PY
+
     - name: Resolve model identifier
       shell: bash
       env: