feat: create HTTP DELETE API endpoints to unregister ScoringFn and Benchmark resources in Llama Stack (#3371)

# What does this PR do?
<!-- Provide a short summary of what this PR does and why. Link to
relevant issues if applicable. -->
This PR provides functionality for users to unregister ScoringFn and
Benchmark resources for `scoring` and `eval` APIs.

<!-- If resolving an issue, uncomment and update the line below -->
<!-- Closes #[issue-number] -->
Closes #3051 

## Test Plan
<!-- Describe the tests you ran to verify your changes with result
summaries. *Provide clear instructions so the plan can be easily
re-executed.* -->
Updated integration and unit tests via CI workflow

llama_stack/providers/remote/eval/nvidia/eval.py

@@ -51,18 +51,23 @@ class NVIDIAEvalImpl(
 
     async def shutdown(self) -> None: ...
 
-    async def _evaluator_get(self, path):
+    async def _evaluator_get(self, path: str):
         """Helper for making GET requests to the evaluator service."""
         response = requests.get(url=f"{self.config.evaluator_url}{path}")
         response.raise_for_status()
         return response.json()
 
-    async def _evaluator_post(self, path, data):
+    async def _evaluator_post(self, path: str, data: dict[str, Any]):
         """Helper for making POST requests to the evaluator service."""
         response = requests.post(url=f"{self.config.evaluator_url}{path}", json=data)
         response.raise_for_status()
         return response.json()
 
+    async def _evaluator_delete(self, path: str) -> None:
+        """Helper for making DELETE requests to the evaluator service."""
+        response = requests.delete(url=f"{self.config.evaluator_url}{path}")
+        response.raise_for_status()
+
     async def register_benchmark(self, task_def: Benchmark) -> None:
         """Register a benchmark as an evaluation configuration."""
         await self._evaluator_post(
@@ -75,6 +80,10 @@ class NVIDIAEvalImpl(
             },
         )
 
+    async def unregister_benchmark(self, benchmark_id: str) -> None:
+        """Unregister a benchmark evaluation configuration from NeMo Evaluator."""
+        await self._evaluator_delete(f"/v1/evaluation/configs/{DEFAULT_NAMESPACE}/{benchmark_id}")
+
     async def run_eval(
         self,
         benchmark_id: str,