Canonicalwebteam.flask-base

Update dependencies: jinja2, Werkzeug, markupsafe, itsdangerous

Fix forwarded IP header to use `X-Original-Forwarded-For` in priority over `X-Forwarded-For`.

Revert `2.1.0` changes to compression of JS and CSS assets

- Add support for Python 3.12
- Update dependencies: talisker, Werkzeug
- Remove unused direct dependencies that are used by talisker: gevent, jinja2, markupsafe, itsdangerous gevent, jinja2, markupsafe, itsdangerous

Upgrade notes

This version will require changes in the `Dockerfile` to use a virtual environment as this is mandatory for Python 3.12.

Here is an example of how to upgrade to `2.2.0`: [canonical/ubuntu.com82f04d9](https://github.com/canonical/ubuntu.com/pull/14699/commits/82f04d909c81f4495669b1dbc28b7051e77ca2f2)