chore(deps): bump tmp and gatsby in /site

Bumps [tmp](https://github.com/raszi/node-tmp) to 0.2.4 and updates ancestor dependency [gatsby](https://github.com/gatsbyjs/gatsby). These dependencies need to be updated together.


Updates `tmp` from 0.0.33 to 0.2.4
- [Changelog](https://github.com/raszi/node-tmp/blob/master/CHANGELOG.md)
- [Commits](raszi/node-tmp@v0.0.33...v0.2.4)

Updates `gatsby` from 5.14.0 to 5.14.6
- [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]@5.14.6)

---
updated-dependencies:
- dependency-name: tmp
  dependency-version: 0.2.4
  dependency-type: indirect
- dependency-name: gatsby
  dependency-version: 5.14.6
  dependency-type: direct:production
...

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

Author: dependabot[bot]