Update doc generation dependencies

Update doc generation dependencies to match latest in main branch.

Signed-off-by: David Enyeart <enyeart@us.ibm.com>

docs/requirements.txt

@@ -1,16 +1,24 @@
 # SPDX-License-Identifier: Apache-2.0
-python-markdown-math==0.2
-
-alabaster==0.7.8
-Babel==2.3.4
-docutils==0.12
-imagesize==0.7.1
-Jinja2==2.10.1
-MarkupSafe==0.23
-Pygments==2.1.3
-pytz==2016.4
-six==1.10.0
-snowballstemmer==1.2.1
-Sphinx==1.7.2
-sphinx-rtd-theme==0.2.5b2
-recommonmark==0.4.0
+alabaster==0.7.13
+Babel==2.12.1
+certifi==2023.7.22
+charset-normalizer==3.2.0
+commonmark==0.9.1
+docutils==0.17.1
+idna==3.4
+imagesize==1.4.1
+Jinja2==3.0.3
+MarkupSafe==2.1.3
+packaging==23.1
+Pygments==2.15.1
+pytz==2023.3
+recommonmark==0.7.1
+requests==2.31.0
+six==1.16.0
+snowballstemmer==2.2.0
+Sphinx==1.8.6
+sphinx-rtd-theme==1.2.2
+sphinxcontrib-jquery==4.1
+sphinxcontrib-serializinghtml==1.1.5
+sphinxcontrib-websupport==1.2.4
+urllib3==1.26.18