Stop ignoring typing on contourpy

It has had types since 1.0.7, which is slightly newer than our
requirement, but this change is only the test files anyway.

Author: QuLogic

lib/matplotlib/tests/test_contour.py

@@ -3,7 +3,7 @@
 import re
 from unittest import mock
 
-import contourpy  # type: ignore
+import contourpy
 import numpy as np
 from numpy.testing import (
     assert_array_almost_equal, assert_array_almost_equal_nulp, assert_array_equal)