chore(deps): update jinja2 requirement in /site-template

Updates the requirements on [jinja2](https://github.com/pallets/jinja) to permit the latest version.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/main/CHANGES.rst)
- [Commits](pallets/jinja@3.1.0...3.1.6)

---
updated-dependencies:
- dependency-name: jinja2
  dependency-version: 3.1.6
  dependency-type: direct:production
...

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

Author: dependabot[bot]

site-template/requirements.txt

@@ -1 +1 @@
-Jinja2>=3.1,<4.0
+Jinja2>=3.1.6,<4.0