Update dependency stylelint to v16.21.1 (#542)

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

Author: renovate[bot]

package-lock.json

@@ -45,7 +45,7 @@
     "postcss": "8.5.6",
     "prettier": "3.6.2",
     "remark-cli": "12.0.1",
-    "stylelint": "16.21.0"
+    "stylelint": "16.21.1"
   },
   "peerDependencies": {
     "stylelint": "^16.0.0"