Bump stylelint from 9.10.1 to 15.10.1 in /samples/react-calendar

Bumps [stylelint](https://github.com/stylelint/stylelint) from 9.10.1 to 15.10.1.
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](https://github.com/stylelint/stylelint/compare/9.10.1...15.10.1)

---
updated-dependencies:
- dependency-name: stylelint
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

samples/react-calendar/package.json

@@ -69,7 +69,7 @@
     "jest": "^23.6.0",
     "karma-junit-reporter": "^1.2.0",
     "spfx-uifabric-themes": "^0.6.0",
-    "stylelint": "^9.10.1",
+    "stylelint": "^15.10.1",
     "stylelint-config-standard": "^18.2.0",
     "stylelint-scss": "^3.5.4",
     "webpack-bundle-analyzer": "^3.1.0"