Bump jinja2 from 3.1.4 to 3.1.6 in /backend/src in the pip group

Bumps the pip group in /backend/src with 1 update: [jinja2](https://github.com/pallets/jinja).


Updates `jinja2` from 3.1.4 to 3.1.6
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/main/CHANGES.rst)
- [Commits](pallets/jinja@3.1.4...3.1.6)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

backend/src/requirements.txt

@@ -2,7 +2,7 @@ blinker==1.9.0
 click==8.1.7
 Flask==3.1.0
 itsdangerous==2.2.0
-Jinja2==3.1.4
+Jinja2==3.1.6
 MarkupSafe==3.0.2
 Werkzeug==3.0.6
 gunicorn==23.0.0