chore(deps): update dependency sinon to v21

Author: renovate[bot]

package.json

@@ -108,7 +108,7 @@
     "mocha": "^11.5.0",
     "rimraf": "^6.0.1",
     "simulant": "^0.2.2",
-    "sinon": "^20.0.0",
+    "sinon": "^21.1.1",
     "typescript": "^5.8.3",
     "webpack": "^5.99.9"
   },