test: remove unused variable from test

ROOT CAUSE:
Ruff linting failed due to unused variable 'resolver' in test_dependency_resolution_missing_dep.

CHANGES:
- Removed unused DependencyResolver instantiation

IMPACT:
- Fixes Ruff linting error in CI
- Test behavior unchanged (resolver was not being used)

Refs: #2081

Author: peter-luminova

tests/server/mcpserver/utilities/test_dependencies.py

@@ -190,7 +190,6 @@ async def tool_func(value: str = Depends(get_value)) -> str:
         # Manually add a dependency that doesn't exist in signature
         tool.dependency_kwarg_names.append("nonexistent")
 
-        resolver = DependencyResolver()
         # This should handle the missing dependency gracefully
         # (in practice this shouldn't happen, but we need to test the branch)
         deps = find_dependency_parameters(tool_func)