Unpin Sphinx version

Author: mgeier

setup.py

@@ -29,8 +29,7 @@
         'nbconvert>=5.3,!=5.4',
         'traitlets>=5',
         'nbformat',
-        # https://github.com/spatialaudio/nbsphinx/issues/825
-        'sphinx >= 1.8, < 8.2',
+        'sphinx >= 1.8, != 8.2.0, != 8.2.1',
     ],
     author='Matthias Geier',
     author_email='[email protected]',