fix(deps): update font awesome to v6 (#281)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package-lock.json

@@ -57,10 +57,10 @@
   },
   "dependencies": {
     "@edx/paragon": "20.27.0",
-    "@fortawesome/fontawesome-svg-core": "1.2.36",
-    "@fortawesome/free-brands-svg-icons": "5.15.4",
-    "@fortawesome/free-regular-svg-icons": "5.15.4",
-    "@fortawesome/free-solid-svg-icons": "5.15.4",
+    "@fortawesome/fontawesome-svg-core": "6.2.1",
+    "@fortawesome/free-brands-svg-icons": "6.2.1",
+    "@fortawesome/free-regular-svg-icons": "6.2.1",
+    "@fortawesome/free-solid-svg-icons": "6.2.1",
     "@fortawesome/react-fontawesome": "^0.2.0",
     "babel-polyfill": "6.26.0",
     "react-responsive": "8.2.0",