Bump git2 from 0.13.6 to 0.13.8
Bump git2 from 0.13.6 to 0.13.8

Bumps [git2](https://github.com/rust-lang/git2-rs) from 0.13.6 to 0.13.8.
- [Release notes](https://github.com/rust-lang/git2-rs/releases)
- [Commits](https://github.com/rust-lang/git2-rs/compare/0.13.6...0.13.8)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
jasonwhite/git-subset,jasonwhite/git-subset