Update dependency less to v4

Author: renovate[bot]

external/forkawesome/package.json

@@ -24,7 +24,7 @@
   "dependencies": {},
   "devDependencies": {
     "all-contributors-cli": "^6.1.1",
-    "less": "^2.7.3",
+    "less": "^4.0.0",
     "less-plugin-clean-css": "^1.5.1",
     "svgo": "^1.1.1"
   },