mypy fixup

Author: jbrockmendel

pandas/core/arrays/_arrow_string_mixins.py

@@ -94,10 +94,7 @@ def _str_get(self, i: int) -> Self:
         selected = pc.utf8_slice_codeunits(
             self._pa_array, start=start, stop=stop, step=step
         )
-        null_value = pa.scalar(
-            None,
-            type=self._pa_array.type,  # type: ignore[attr-defined]
-        )
+        null_value = pa.scalar(None, type=self._pa_array.type)
         result = pc.if_else(not_out_of_bounds, selected, null_value)
         return type(self)(result)