Bump shell-quote and gatsby

Bumps [shell-quote](https://github.com/ljharb/shell-quote) to 1.8.0 and updates ancestor dependency [gatsby](https://github.com/gatsbyjs/gatsby). These dependencies need to be updated together.


Updates `shell-quote` from 1.6.1 to 1.8.0
- [Release notes](https://github.com/ljharb/shell-quote/releases)
- [Changelog](https://github.com/ljharb/shell-quote/blob/main/CHANGELOG.md)
- [Commits](ljharb/shell-quote@1.6.1...v1.8.0)

Updates `gatsby` from 2.32.13 to 5.6.0
- [Release notes](https://github.com/gatsbyjs/gatsby/releases)
- [Changelog](https://github.com/gatsbyjs/gatsby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/gatsbyjs/gatsby/compare/[email protected]@5.6.0)

---
updated-dependencies:
- dependency-name: shell-quote
  dependency-type: indirect
- dependency-name: gatsby
  dependency-type: direct:development
...

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

Author: dependabot[bot]