fix!: update eval-tasks -> benchmarks (#1032)

# What does this PR do?

- Update `/eval-tasks` to `/benchmarks`
- ⚠️ Remove differentiation between `app` v.s. `benchmark` eval task
config. Now we only have `BenchmarkConfig`. The overloaded `benchmark`
is confusing and do not add any value. Backward compatibility is being
kept as the "type" is not being used anywhere.

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])

## Test Plan
- This change is backward compatible 
- Run notebook test with

```
pytest -v -s --nbval-lax ./docs/getting_started.ipynb
pytest -v -s --nbval-lax ./docs/notebooks/Llama_Stack_Benchmark_Evals.ipynb
```

<img width="846" alt="image"
src="https://github.com/user-attachments/assets/d2fc06a7-593a-444f-bc1f-10ab9b0c843d"
/>



[//]: # (## Documentation)
[//]: # (- [ ] Added a Changelog entry if the change is significant)

---------

Signed-off-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>
Signed-off-by: Ben Browning <bbrownin@redhat.com>
Signed-off-by: Sébastien Han <seb@redhat.com>
Signed-off-by: reidliu <reid201711@gmail.com>
Co-authored-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>
Co-authored-by: Ben Browning <ben324@gmail.com>
Co-authored-by: Sébastien Han <seb@redhat.com>
Co-authored-by: Reid <61492567+reidliu41@users.noreply.github.com>
Co-authored-by: reidliu <reid201711@gmail.com>
Co-authored-by: Yuan Tang <terrytangyuan@gmail.com>

llama_stack/providers/tests/resolver.py

@@ -10,8 +10,8 @@ from typing import Any, Dict, List, Optional
 
 from pydantic import BaseModel
 
+from llama_stack.apis.benchmarks import BenchmarkInput
 from llama_stack.apis.datasets import DatasetInput
-from llama_stack.apis.eval_tasks import EvalTaskInput
 from llama_stack.apis.models import ModelInput
 from llama_stack.apis.scoring_functions import ScoringFnInput
 from llama_stack.apis.shields import ShieldInput
@@ -42,7 +42,7 @@ async def construct_stack_for_test(
     vector_dbs: Optional[List[VectorDBInput]] = None,
     datasets: Optional[List[DatasetInput]] = None,
     scoring_fns: Optional[List[ScoringFnInput]] = None,
-    eval_tasks: Optional[List[EvalTaskInput]] = None,
+    benchmarks: Optional[List[BenchmarkInput]] = None,
     tool_groups: Optional[List[ToolGroupInput]] = None,
 ) -> TestStack:
     sqlite_file = tempfile.NamedTemporaryFile(delete=False, suffix=".db")
@@ -56,7 +56,7 @@ async def construct_stack_for_test(
         vector_dbs=vector_dbs or [],
         datasets=datasets or [],
         scoring_fns=scoring_fns or [],
-        eval_tasks=eval_tasks or [],
+        benchmarks=benchmarks or [],
         tool_groups=tool_groups or [],
     )
     run_config = parse_and_maybe_upgrade_config(run_config)