Fix astropy pytest header import
# no matter how it is invoked within the source tree.
import os
from astropy.tests.helper import enable_deprecations_as_exceptions
-from astropy.tests.plugins.display import PYTEST_HEADER_MODULES
+from pytest_astropy_header.display import PYTEST_HEADER_MODULES
# TODO: add numpy again once https://github.com/astropy/regions/pull/252 is addressed
enable_deprecations_as_exceptions(warnings_to_ignore_entire_module=["numpy", "astropy"])
