Pin Cython < 3 at least until we upgrade to lxml 5+

python-lxml.spec

@@ -68,6 +68,8 @@ Python 3 version.
 %autosetup -n lxml-%{version} -p1
 # Don't run html5lib tests --without extras
 %{!?without_extras:rm src/lxml/html/tests/test_html5parser.py}
+# lxml 4.9 is not yet ready for Cython 3
+sed -Ei 's/Cython>=([^,]+)/Cython>=\1,<3/' requirements.txt
 
 %generate_buildrequires
 %pyproject_buildrequires -x source%{?with_extras:,cssselect,html5,htmlsoup}