Bump stylelint from 13.12.0 to 15.10.1 in /core/assets

Bumps [stylelint](https://github.com/stylelint/stylelint) from 13.12.0 to 15.10.1.
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](stylelint/stylelint@13.12.0...15.10.1)

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

Signed-off-by: dependabot[bot] <[email protected]>