Merge pull request IQSS#9076 from j-n-c/9074-sphynx-python3_10

IQSS#9074 - Added support for building sphinx docs using python 3.10+

Author: kcondon

doc/sphinx-guides/requirements.txt

@@ -1,5 +1,10 @@
-# current version as of this writing
-Sphinx==3.5.4
+# Developers, please use Python 3.9 or lower to build the guides.
+# For your convenience, a solution for Python 3.10 is provided below
+# but we would prefer that you use the same version of Sphinx
+# (below on the < 3.10 line) that is used to build the production guides.
+Sphinx==3.5.4 ; python_version < '3.10'
+Sphinx==5.3.0 ; python_version >= '3.10'
+
 # Necessary workaround for ReadTheDocs for Sphinx 3.x - unnecessary as of Sphinx 4.5+
 Jinja2>=3.0.2,<3.1