Update shopsys/shopsys to fix integration tests - #15058

Executing script composer security-check [KO]
 [KO]
Script composer security-check returned with error code 1
!!  [CRITICAL] 1 package has known vulnerabilities
!!  
!!  squizlabs/php_codesniffer (3.13.5)
!!  ----------------------------------
!!  
!!   * CVE-2026-67434: OS Command injection
!!     https://github.com/PHPCSStandards/PHP_CodeSniffer/security/advisories/GHSA-hmqg-cxww-wqhq
!!  
!!  Script security-checker security:check handling the security-check event returned with error code 1
!!