Bump toml from 0.4.10 to 0.5.1

Bumps [toml](https://github.com/alexcrichton/toml-rs) from 0.4.10 to 0.5.1.
- [Release notes](https://github.com/alexcrichton/toml-rs/releases)
- [Commits](https://github.com/alexcrichton/toml-rs/compare/0.4.10...0.5.1

)

Signed-off-by: dependabot[bot] <support@dependabot.com>