BUG: Add numpy installation for Windows wheels testing

Author: thewtex

scripts/windows_build_wheels.py

@@ -233,6 +233,7 @@ def test_wheels(python_env):
         ninja_executable,
         path
     ) = venv_paths(python_env)
+    check_call([pip, 'install', 'numpy'])
     check_call([pip, 'install', 'itk', '--no-cache-dir', '--no-index',
         '-f', 'dist'])
     print('Wheel successfully installed.')