bump pytest

reqs/requirements-dev-lite.txt

@@ -9,7 +9,7 @@ nbconvert>=5
 nbformat>=5.0
 pact-python>=2.0.1
 pyfakefs>=4.5.1
-pytest>=7.2,<8.0  # 8.0 seems to have undocumented change to pytest.warns(SomeWarning) that breaks spark tests
+pytest>=8.2.1,<9.0
 pytest-benchmark>=3.4.1
 pytest-cov>=5.0.0
 pytest-icdiff>=0.6