chore(deps-dev): bump @antv/g2 from 5.1.7 to 5.1.8

Bumps [@antv/g2](https://github.com/antvis/g2) from 5.1.7 to 5.1.8.
- [Release notes](https://github.com/antvis/g2/releases)
- [Changelog](https://github.com/antvis/G2/blob/v5/CHANGELOG.md)
- [Commits](antvis/G2@5.1.7...5.1.8)

---
updated-dependencies:
- dependency-name: "@antv/g2"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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