chore: update dependency stylelint to ^16.21.0

Author: renovate[bot]

packages/stylelint-config-smarthr/package.json

@@ -31,7 +31,7 @@
     "jest": "^30.0.0",
     "postcss-styled-syntax": "^0.7.1",
     "styled-components": "^6.1.19",
-    "stylelint": "^16.20.0",
+    "stylelint": "^16.21.0",
     "stylelint-config-sass-guidelines": "^12.1.0",
     "stylelint-config-standard": "^38.0.0",
     "vitest": "^3.2.4"