Fixed all ruff issues

tests/test_memory_edge_cases.py

@@ -390,9 +390,8 @@ class TestMemoryEdgeCases:
         """Should create directory if not exists."""
         new_dir = temp_dir / "new" / "nested" / "dir"
 
-        # Create parent directories first
-        new_dir.mkdir(parents=True, exist_ok=True)
-        memory = Memory(storage_dir=str(new_dir))
+        # Don't create the directory - let Memory do it
+        Memory(storage_dir=str(new_dir))
 
         assert new_dir.exists()
 
@@ -405,7 +404,7 @@ class TestMemoryEdgeCases:
         try:
             os.chmod(readonly_dir, 0o444)
             # This might raise or might work depending on OS
-            memory = Memory(storage_dir=str(readonly_dir))
+            Memory(storage_dir=str(readonly_dir))
         except (PermissionError, OSError):
             pass  # Expected on some systems
         finally:
@@ -512,7 +511,7 @@ class TestMemoryContextEdgeCases:
         """Should handle multiple init calls."""
         _memory_ctx.set(None)
 
-        mem1 = init_memory(str(temp_dir))
+        init_memory(str(temp_dir))
         mem2 = init_memory(str(temp_dir))
 
         # Second call should replace first