Bump jinja2 from 3.0.3 to 3.1.5 in /docs

Bumps [jinja2](https://github.com/pallets/jinja) from 3.0.3 to 3.1.5.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/main/CHANGES.rst)
- [Commits](pallets/jinja@3.0.3...3.1.5)

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

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

docs/requirements.txt

@@ -6,7 +6,7 @@ mkdocstrings==0.17.0     # Autogenerate documentation from docstrings.
 mknotebooks==0.7.1       # Turn Jupyter Lab notebooks into webpages.
 pytkdocs_tweaks==0.0.8   # Tweaks mkdocstrings to improve various aspects
 mkdocs_include_exclude_files==0.0.1  # Allow for customising which files get included
-jinja2==3.0.3            # Older version. After 3.1.0 seems to be incompatible with current versions of mkdocstrings.
+jinja2==3.1.5            # Older version. After 3.1.0 seems to be incompatible with current versions of mkdocstrings.
 nbconvert==6.5.0         # | Older verson to avoid error
 nbformat==5.4.0          # |
 pygments==2.14.0