Bump eslint from 9.19.0 to 9.21.0 (#321)

Author: dependabot[bot]

package-lock.json

@@ -53,7 +53,7 @@
     "@types/sinon-chai": "^3.2.12",
     "chai": "^4.4.1",
     "chai-as-promised": "^7.1.2",
-    "eslint": "^9.19.0",
+    "eslint": "^9.21.0",
     "globals": "^15.14.0",
     "mocha": "^10.8.2",
     "proxyquire": "^2.1.3",