fix: some windows versions don't make this directory?

Author: nedbat

tests/test_venv.py

@@ -213,8 +213,8 @@ def test_third_party_venv_isnt_measured(
             try:
                 run_in_venv("python -m pip install .")
             finally:
-                shutil.rmtree("build")
-                shutil.rmtree("myproduct.egg-info")
+                shutil.rmtree("build", ignore_errors=True)
+                shutil.rmtree("myproduct.egg-info", ignore_errors=True)
             # Ensure that coverage doesn't run the non-installed module.
             os.remove('myproduct.py')
             out = run_in_venv(coverage_command + " run --source=.,myproduct -m myproduct")