build(deps-dev): bump @types/babel__generator from 7.6.7 to 7.6.8

Bumps [@types/babel__generator](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/babel__generator) from 7.6.7 to 7.6.8.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/babel__generator)

---
updated-dependencies:
- dependency-name: "@types/babel__generator"
  dependency-type: indirect
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>