Update dependency sinon to v21

Author: renovate[bot]

package-lock.json

@@ -36,7 +36,7 @@
   },
   "devDependencies": {
     "codecov": "3.8.3",
-    "sinon": "18.0.1",
+    "sinon": "21.0.0",
     "standard": "17.1.2",
     "express": "4.21.2",
     "mocha": "10.8.2",