Resolve mypy error after git merge master:

```
mypy.....................................................................Failed
- hook id: mypy
- exit code: 1

ubench/holder_comparison.py:96: error: Unused "type: ignore" comment  [unused-ignore]
ubench/holder_comparison.py:97: error: Unused "type: ignore" comment  [unused-ignore]
Found 2 errors in 1 file (checked 12 source files)
```

Author: rwgk

ubench/holder_comparison.py

@@ -93,8 +93,8 @@ def find_call_repetitions(
                     continue
                 if selected_holder_type != "all" and nb_label != selected_holder_type:
                     continue
-                nb1 = nb_type(data_size)  # type: ignore[misc]
-                nb2 = nb_type(data_size)  # type: ignore[misc]
+                nb1 = nb_type(data_size)
+                nb2 = nb_type(data_size)
 
                 def many_sum(call_repetitions: int) -> float:
                     assert int(round(nb1.sum())) == data_size