Add Symfony Security Checker to glubuntu Docker container

Currently, it is required to use the following code to run the Symfony security checker in a Gitlab Pipeline:

security_check:
  stage: test
  image:
    name: $JOB_IMAGE
  script:
    - curl -L  https://github.com/fabpot/local-php-security-checker/releases/download/v1.2.0/local-php-security-checker_1.2.0_linux_386 --output local-php-security-checker
    - chmod +x local-php-security-checker
    - ./local-php-security-checker --format=junit --path=./composer.lock > security-checker-report.xml
  artifacts:
    reports:
      junit:
        - security-checker-report.xml

Maybe, it is a good enhancement to add the security checker to the glubuntu docker image, so it must not be installed on each pipeline run and this step will be faster.