Update dependency chai to v6

Author: renovate[bot]

package-lock.json

@@ -23,7 +23,7 @@
   "author": "Kemal Ahmed <goatandsheep@gmail.com>",
   "license": "MIT",
   "devDependencies": {
-    "chai": "^4.3.0",
+    "chai": "^6.0.0",
     "eslint": "^6.8.0",
     "mocha": "^7.2.0",
     "nyc": "^15.1.0"