Update dependency eslint to v9

Author: renovate[bot]

package.json

@@ -27,7 +27,7 @@
     "@typescript-eslint/eslint-plugin": "2.34.0",
     "@typescript-eslint/parser": "2.34.0",
     "chai": "4.3.4",
-    "eslint": "6.8.0",
+    "eslint": "9.25.0",
     "mocha": "7.2.0",
     "ts-node": "8.10.2",
     "typescript": "3.9.9"