Update babel requirement from ~=2.10 to ~=2.16

Updates the requirements on [babel](https://github.com/python-babel/babel) to permit the latest version.
- [Release notes](https://github.com/python-babel/babel/releases)
- [Changelog](https://github.com/python-babel/babel/blob/master/CHANGES.rst)
- [Commits](https://github.com/python-babel/babel/compare/v2.10.0...v2.16.0)

---
updated-dependencies:
- dependency-name: babel
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/requirements.txt

@@ -29,7 +29,7 @@ pygments~=2.18
 pymdown-extensions~=10.9
 
 # Requirements for plugins
-babel~=2.10
+babel~=2.16
 colorama~=0.4
 paginate~=0.5
 regex>=2022.4