Bump jinja2 from 2.11.3 to 3.1.3 in /doc

Bumps [jinja2](https://github.com/pallets/jinja) from 2.11.3 to 3.1.3.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/main/CHANGES.rst)
- [Commits](pallets/jinja@2.11.3...3.1.3)

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

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

doc/requirements.txt

@@ -1,5 +1,5 @@
 Babel==2.9.1
-Jinja2==2.11.3
+Jinja2==3.1.3
 MarkupSafe==0.23
 Pygments==2.15.0
 Sphinx==1.6.6