CI: fix mypy complaints (#45191)

Author: jbrockmendel

pandas/core/ops/array_ops.py

@@ -5,10 +5,7 @@
 import datetime
 from functools import partial
 import operator
-from typing import (
-    Any,
-    cast,
-)
+from typing import Any
 
 import numpy as np
 
@@ -94,8 +91,6 @@ def _masked_arith_op(x: np.ndarray, y, op):
     assert isinstance(x, np.ndarray), type(x)
     if isinstance(y, np.ndarray):
         dtype = find_common_type([x.dtype, y.dtype])
-        # x and y are both ndarrays -> common_dtype is np.dtype
-        dtype = cast(np.dtype, dtype)
         result = np.empty(x.size, dtype=dtype)
 
         if len(x) != len(y):

pandas/io/stata.py

@@ -1698,13 +1698,13 @@ def read(
             data = DataFrame(columns=self.varlist)
         else:
             data = DataFrame.from_records(raw_data)
-            data.columns = self.varlist
+            data.columns = Index(self.varlist)
 
         # If index is not specified, use actual row number rather than
         # restarting at 0 for each chunk.
         if index_col is None:
-            ix = np.arange(self._lines_read - read_lines, self._lines_read)
-            data.index = ix  # set attr instead of set_index to avoid copy
+            rng = np.arange(self._lines_read - read_lines, self._lines_read)
+            data.index = Index(rng)  # set attr instead of set_index to avoid copy
 
         if columns is not None:
             try: