Fix wheels builder

Author: asvetlov

.mypy.ini

@@ -29,6 +29,3 @@ warn_unused_ignores = True
 
 [mypy-test_incorrect_args]
 disable_error_code = arg-type, call-overload
-
-[mypy-test_capi]
-disable_error_code = attr-defined

tests/test_capi.py

@@ -1,8 +1,8 @@
 import multidict
 import pytest
-import testcapi
 
 pytest.importorskip("multidict._multidict")
+testcapi = pytest.importorskip("testcapi")
 
 pytestmark = pytest.mark.capi