Bump stylelint and stylelint-config-standard in /assets

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 13.13.1 to 14.0.1
- [Release notes](https://github.com/stylelint/stylelint/releases)
- [Changelog](https://github.com/stylelint/stylelint/blob/main/CHANGELOG.md)
- [Commits](stylelint/stylelint@13.13.1...14.0.1)

Updates `stylelint-config-standard` from 22.0.0 to 23.0.0
- [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@22.0.0...23.0.0)

---
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
...

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Author: dependabot[bot]