chore: update dependency sinon to v21 (#57)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -26,7 +26,7 @@
     "eslint-config-eslint": "^13.0.0",
     "globals": "^16.0.0",
     "mocha": "^11.0.0",
-    "sinon": "^18.0.0"
+    "sinon": "^21.0.0"
   },
   "keywords": [
     "javascript",