ISSUE-3924 Bumps mkdocs and associated tools

This attempts to fix #3942 by way of upgrading `mkdocs` and the associated
dependencies. As I mentioned in the issue, it looks like the hamburger menu
glitch has been fixed in `mkdocs-material` upstream.

**NOTE**
I have been unable to test this change. I currently cannot get past an issue
with `plantuml` when I attempt to run the docs with the suggested:
```sh
make install_venv serve -C docs/mkdocs
```

Here is the issue. I get this error on both MacOS and a Ubuntu machine no
matter which branch I am on. I don't see any mention of anyone else
encountering this in another GitHub issue:
```
Exception: Failed to run plantuml: [Errno 2] No such file or directory: 'plantuml'
make: *** [serve] Error 1
```

But in the spirit of FOSS Friday, I wanted to get a PR up anyways. I was at
least able to determine a cascading set of version number dependencies and I
don't want to lose that effort.

Cheers!

docs/mkdocs/requirements.txt

@@ -20,19 +20,19 @@ Markdown==3.3.7            # we cannot install a more recent version yet as mkdo
 markdown-include==0.8.0
 MarkupSafe==2.1.1
 mergedeep==1.3.4
-mkdocs==1.4.2
-mkdocs-git-revision-date-localized-plugin==1.1.0
-mkdocs-material==8.5.11
+mkdocs==1.4.3
+mkdocs-git-revision-date-localized-plugin==1.2.0
+mkdocs-material==9.1.9
 mkdocs-material-extensions==1.1.1
-mkdocs-minify-plugin==0.6.2
+mkdocs-minify-plugin==0.6.4
 mkdocs-redirects==1.2.0
 mkdocs-simple-hooks==0.1.5
 nltk==3.8
 packaging==22.0
 plantuml==0.3.0
-plantuml-markdown==3.7.3
-Pygments==2.13.0
-pymdown-extensions==9.9
+plantuml-markdown==3.9.1
+Pygments==2.14.0
+pymdown-extensions==9.9.1
 pyparsing==3.0.9
 python-dateutil==2.8.2
 pytz==2022.7