fix linting

Author: ndgrigorian

.flake8

@@ -12,6 +12,8 @@ extend-ignore =
     D102,
     # missing docstring in public function:
     D103,
+    # missing docstring in public package:
+    D104,
     # missing docstring in __init__:
     D107,
     # 1 blank line required between summary line and description:

pyproject.toml

@@ -72,7 +72,8 @@ Download = "http://github.com/IntelPython/mkl_umath"
 Homepage = "http://github.com/IntelPython/mkl_umath"
 
 [tool.black]
-extend-exclude = "_vendored/"
+extend-exclude = "(^|/)_vendored/"
+force-exclude = "(^|/)_vendored/"
 line-length = 80
 
 [tool.cython-lint]