Bump toml from 0.7.6 to 0.7.8

Bumps [toml](https://github.com/toml-rs/toml) from 0.7.6 to 0.7.8.
- [Commits](toml-rs/toml@toml-v0.7.6...toml-v0.7.8)

---
updated-dependencies:
- dependency-name: toml
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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