Bump @fortawesome/fontawesome-free from 5.15.4 to 6.4.0

Bumps [@fortawesome/fontawesome-free](https://github.com/FortAwesome/Font-Awesome) from 5.15.4 to 6.4.0.
- [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@5.15.4...6.4.0)

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

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

package.json

@@ -105,7 +105,7 @@
     "webpack-deadcode-plugin": "^0.1.15"
   },
   "dependencies": {
-    "@fortawesome/fontawesome-free": "^5.15.4",
+    "@fortawesome/fontawesome-free": "^6.4.0",
     "@hms-dbmi-bgm/react-workflow-viz": "0.1.7",
     "@hms-dbmi-bgm/shared-portal-components": "git+https:github.com/4dn-dcic/shared-portal-components#0.1.64",
     "auth0-lock": "^11.33.1",