chore: Bump stylelint and stylelint-config-standard in /frontend (#557)

Bumps [stylelint](https://github.com/stylelint/stylelint) and [stylelint-config-standard](https://github.com/stylelint/stylelint-config-standard). These dependencies needed to be updated together.

Updates `stylelint` from 15.11.0 to 16.0.1
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](stylelint/stylelint@15.11.0...16.0.1)

Updates `stylelint-config-standard` from 34.0.0 to 35.0.0
- [Release notes](https://github.com/stylelint/stylelint-config-standard/releases)
- [Changelog](https://github.com/stylelint/stylelint-config-standard/blob/main/CHANGELOG.md)
- [Commits](stylelint/stylelint-config-standard@34.0.0...35.0.0)

---
updated-dependencies:
- dependency-name: stylelint
  dependency-type: direct:development
  update-type: version-update:semver-major
- dependency-name: stylelint-config-standard
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>