Remove 'from cibuildwheel import linux, macos, windows' from new tests, as imports are done in fixtures

unit_test/main_options_test.py

@@ -2,7 +2,6 @@ import pytest
 
 import sys
 
-from cibuildwheel import linux, macos, windows
 from cibuildwheel.__main__ import main
 from cibuildwheel.environment import ParsedEnvironment
 from cibuildwheel.util import BuildSelector

unit_test/main_platform_test.py

@@ -3,7 +3,6 @@ import pytest
 import sys
 
 from cibuildwheel.__main__ import main
-from cibuildwheel import linux, macos, windows
 
 from main_util_fixtures import MOCK_PROJECT_DIR, mock_protection, platform, intercepted_build_args