Update xml-rs requirement from 0.7.0 to 0.8.0
Update xml-rs requirement from 0.7.0 to 0.8.0

Updates the requirements on [xml-rs](https://github.com/netvl/xml-rs) to permit the latest version.
- [Release notes](https://github.com/netvl/xml-rs/releases)
- [Changelog](https://github.com/netvl/xml-rs/blob/master/Changelog.md)
- [Commits](https://github.com/netvl/xml-rs/commits)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
bjz/gl-rs,bjz/gl-rs