test_nothing_to_render_raises_warning fails on Sphinx v8.1

[cclauss]

Related to #490 --> sphinx>=6.1.0,<8.1.0

https://github.com/sphinx-doc/sphinx/releases

=================================== FAILURES ===================================
____________________ test_nothing_to_render_raises_warning _____________________

builder = <function builder..build at 0x10bbdce00>

  def test_nothing_to_render_raises_warning(builder):

  with pytest.raises(sphinx.errors.SphinxWarning) as exc_info:

E Failed: DID NOT RAISE <class 'sphinx.errors.SphinxWarning'>

/Users/runner/work/sphinx-autoapi/sphinx-autoapi/tests/python/test_pyintegration.py:1309: Failed

sphinx-autoapi/tests/python/test_pyintegration.py

Lines 1308 to 1312 in b71782a

	def test_nothing_to_render_raises_warning(builder):
	with pytest.raises(sphinx.errors.SphinxWarning) as exc_info:
	builder("pynorender", warningiserror=True)
	assert "No modules were rendered" in str(exc_info.value)

@AA-Turner