Bump squizlabs/php_codesniffer from 3.10.3 to 3.11.1 in /_backend

Bumps [squizlabs/php_codesniffer](https://github.com/PHPCSStandards/PHP_CodeSniffer) from 3.10.3 to 3.11.1.
- [Release notes](https://github.com/PHPCSStandards/PHP_CodeSniffer/releases)
- [Changelog](https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/CHANGELOG.md)
- [Commits](PHPCSStandards/PHP_CodeSniffer@3.10.3...3.11.1)

---
updated-dependencies:
- dependency-name: squizlabs/php_codesniffer
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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