Bump jinja2 from 3.0.0 to 3.1.4 in /docs

Bumps [jinja2](https://github.com/pallets/jinja) from 3.0.0 to 3.1.4.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/main/CHANGES.rst)
- [Commits](https://github.com/pallets/jinja/compare/3.0.0...3.1.4)

---
updated-dependencies:
- dependency-name: jinja2
  dependency-type: direct:production
...

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

docs/requirements.txt

@@ -1,5 +1,5 @@
 parse_cmake
 sphinx==1.8.5
 docutils==0.17.1
-jinja2==3.0.0
+jinja2==3.1.4
 sphinx_rtd_theme