[Security] Bump wagtail from 2.8 to 2.8.1
[Security] Bump wagtail from 2.8 to 2.8.1

Bumps [wagtail](https://github.com/wagtail/wagtail) from 2.8 to 2.8.1. **This update includes a security fix.**
- [Release notes](https://github.com/wagtail/wagtail/releases)
- [Changelog](https://github.com/wagtail/wagtail/blob/master/CHANGELOG.txt)
- [Commits](https://github.com/wagtail/wagtail/compare/v2.8...v2.8.1)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
Frojd/wagtail-geo-widget,Frojd/wagtail-geo-widget,Frojd/wagtail-geo-widget,Frojd/wagtail-geo-widget