chore(deps): update font awesome to v6

Author: renovate[bot]

package-lock.json

@@ -23,9 +23,9 @@
   },
   "devDependencies": {
     "@akebifiky/remark-simple-plantuml": "1.0.2",
-    "@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/free-brands-svg-icons": "6.4.2",
+    "@fortawesome/free-regular-svg-icons": "6.4.2",
+    "@fortawesome/free-solid-svg-icons": "6.4.2",
     "@mdi/js": "6.4.95",
     "@nuxt/image": "0.6.0",
     "@nuxtjs/fontawesome": "1.1.2",