Use a more robust way to fail the tests if an env var is set

Author: asmeurer

array_api_strict/tests/conftest.py

@@ -4,7 +4,7 @@
 
 import pytest
 
-def pytest_sessionstart(session):
+def pytest_configure(config):
     for env_var in ENVIRONMENT_VARIABLES:
         if env_var in os.environ:
             pytest.exit(f"ERROR: {env_var} is set. array-api-strict environment variables must not be set when the tests are run.")