[Perf] Validate @config in pre-commit instead of dynamically (#20200)

Signed-off-by: Lionel Villard <villard@us.ibm.com>

.pre-commit-config.yaml

@@ -160,6 +160,13 @@ repos:
     types: [python]
     pass_filenames: false
     additional_dependencies: [pathspec, regex]
+  - id: validate-config
+    name: Validate configuration has default values and that each field has a docstring
+    entry: python tools/validate_config.py
+    language: python
+    types: [python]
+    pass_filenames: true
+    files: vllm/config.py|tests/test_config.py
   # Keep `suggestion` last
   - id: suggestion
     name: Suggestion