Update sphinx dependencies.

source/docs/apps/python-venv.rst

@@ -59,14 +59,18 @@ Environments may be exported for easy configuration with services and scripts.
   python3 -m pip install --requirement {ENV CONFIG}
 
 Updating Environments
-=====================
+*********************
 Update environment and re-export.
 
+.. important::
+  ``requirements.txt`` ({ENV CONFIG}) must be updated to use **>=** before
+  attempting to update.
+
 .. code-block::
   :caption: Update environment.
 
   . {ENV DIR}/bin/activate
-  python3 -m pip install --upgrade --requirement {ENV CONFIG}
+  python3 -m pip install --requirement {ENV CONFIG} --upgrade
   python3 -m pip freeze > {ENV CONFIG}
 
 .. rubric:: References

sphinx/requirements.txt

@@ -1,31 +1,32 @@
 aafigure==0.6
 alabaster==0.7.12
-attrs==20.3.0
-Babel==2.9.0
-certifi==2020.12.5
-chardet==3.0.4
-docutils==0.16
-idna==2.10
-imagesize==1.2.0
-Jinja2==2.11.2
-MarkupSafe==1.1.1
-packaging==20.8
-Pygments==2.7.3
-pyparsing==2.4.7
-pytz==2020.4
-requests==2.25.0
-six==1.15.0
-snowballstemmer==2.0.0
-Sphinx==3.3.1
-sphinx-copybutton==0.3.1
-sphinx-panels==0.5.2
-sphinx-rtd-theme==0.5.0
+attrs==22.1.0
+Babel==2.10.3
+certifi==2022.9.24
+chardet==5.0.0
+charset-normalizer==2.1.1
+docutils==0.17.1
+idna==3.4
+imagesize==1.4.1
+Jinja2==3.1.2
+MarkupSafe==2.1.1
+packaging==21.3
+Pygments==2.13.0
+pyparsing==3.0.9
+pytz==2022.4
+requests==2.28.1
+six==1.16.0
+snowballstemmer==2.2.0
+Sphinx==4.5.0
+sphinx-copybutton==0.5.0
+sphinx-panels==0.6.0
+sphinx-rtd-theme==1.0.0
+sphinx_collapse==0.1.2
 sphinxcontrib-aafig2==1.2
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-devhelp==1.0.2
-sphinxcontrib-htmlhelp==1.0.3
+sphinxcontrib-htmlhelp==2.0.0
 sphinxcontrib-jsmath==1.0.1
 sphinxcontrib-qthelp==1.0.3
-sphinxcontrib-serializinghtml==1.1.4
-sphinx-collapse==0.1.2
-urllib3==1.26.2
+sphinxcontrib-serializinghtml==1.1.5
+urllib3==1.26.12