chore(deps): update dependency @types/sinon to v21

Author: renovate[bot]

package.json

@@ -20,7 +20,7 @@
     "@types/ip-address": "7.0.0",
     "@types/mocha": "^10.0.1",
     "@types/node": "24.9.2",
-    "@types/sinon": "17.0.4",
+    "@types/sinon": "21.0.0",
     "ip-address": "10.0.1",
     "mocha": "^11.0.0",
     "prettier": "^3.5.3",