Bump @fortawesome/free-solid-svg-icons from 6.5.1 to 6.6.0 in /frontend

Bumps [@fortawesome/free-solid-svg-icons](https://github.com/FortAwesome/Font-Awesome) from 6.5.1 to 6.6.0.
- [Release notes](https://github.com/FortAwesome/Font-Awesome/releases)
- [Changelog](https://github.com/FortAwesome/Font-Awesome/blob/6.x/CHANGELOG.md)
- [Commits](https://github.com/FortAwesome/Font-Awesome/compare/6.5.1...6.6.0)

---
updated-dependencies:
- dependency-name: "@fortawesome/free-solid-svg-icons"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

frontend/package.json

@@ -78,7 +78,7 @@
     "@fortawesome/angular-fontawesome": "~0.14.1",
     "@fortawesome/fontawesome-common-types": "~6.5.1",
     "@fortawesome/fontawesome-svg-core": "~6.6.0",
-    "@fortawesome/free-solid-svg-icons": "~6.5.1",
+    "@fortawesome/free-solid-svg-icons": "~6.6.0",
     "@mempool/mempool.js": "2.3.0",
     "@ng-bootstrap/ng-bootstrap": "^16.0.0",
     "@types/qrcode": "~1.5.0",