build(deps): bump @fortawesome/fontawesome-free from 6.4.0 to 6.4.2

Bumps [@fortawesome/fontawesome-free](https://github.com/FortAwesome/Font-Awesome) from 6.4.0 to 6.4.2.
- [Release notes](https://github.com/FortAwesome/Font-Awesome/releases)
- [Changelog](https://github.com/FortAwesome/Font-Awesome/blob/6.x/CHANGELOG.md)
- [Commits](FortAwesome/Font-Awesome@6.4.0...6.4.2)

---
updated-dependencies:
- dependency-name: "@fortawesome/fontawesome-free"
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -8,7 +8,7 @@
  "@asciidoctor/core": "^2.2.6",
  "@emotion/react": "^11.11.1",
  "@emotion/styled": "^11.11.0",
- "@fortawesome/fontawesome-free": "^6.4.0",
+ "@fortawesome/fontawesome-free": "^6.4.2",
  "@gatsbyjs/reach-router": "^2.0.1",
  "@mdx-js/react": "^2.3.0",
  "@mui/lab": "^5.0.0-alpha.134",