Remove --build xfail for now

The option is current restored. We should remove this test after the
option is removed (again).

Author: uranusjr

tests/functional/test_wheel.py

@@ -240,7 +240,6 @@ def test_pip_wheel_fail(script, data):
     assert result.returncode != 0
 
 
-@pytest.mark.xfail(reason="The --build option was removed")
 def test_no_clean_option_blocks_cleaning_after_wheel(
     script,
     data,