chore(deps): update devdependency eslint to v9.21.0

Author: renovate[bot]

package.json

@@ -62,7 +62,7 @@
     "@typescript-eslint/parser": "8.24.1",
     "@vitest/coverage-v8": "3.0.5",
     "bumpp": "10.0.3",
-    "eslint": "9.20.1",
+    "eslint": "9.21.0",
     "execa": "9.5.2",
     "get-port-please": "3.1.2",
     "lint-staged": "15.4.3",