Update stylelint requirement from ^13.6.1 to ^13.11.0
Update stylelint requirement from ^13.6.1 to ^13.11.0

Updates the requirements on [stylelint](https://github.com/stylelint/stylelint) to permit the latest version.
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/stylelint/stylelint/compare/13.6.1...13.11.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
coliff/bootstrap-ie8