Using Symfony CLI image on Gitlab CI/CD: "sh" does not exist

GitLab instance: gitlab.com
GitLab runner: shared @ v13.8.0 (775dd39d)

I would like to use the Symfony CLI to run their security checker command in a CI/CD pipeline. This page describes how to do that with the official Docker image: https://symfony.com/blog/the-php-security-checker-as-a-docker-image.

docker run --rm -v $(pwd):$(pwd) -w $(pwd) symfonycorp/cli check:security

Now, to run this in a CI/CD pipeline I tried the following .gitlab-ci.yml file:

image: gitlab/dind:latest

stages:
    - check

security-checker:
    stage: check
    image: symfonycorp/cli
    script:
        - check:security

The step fails with the following error:

Executing "step_script" stage of the job script
                               
 Command "sh" does not exist.  
 Did you mean one of these?    
     env:ssh                   
     local:php:refresh         
     ssh                       

I suspect this is because this image defines a custom entrypoint:

 ENTRYPOINT ["/symfony"]

Source: https://hub.docker.com/layers/symfonycorp/cli/latest/images/sha256-c1d742d39037c359f463d0b56d89a6b8c8bf1017570cc4fee06fca1d77d844bd?context=explore

The “sh does not exist” error pops up quite a lot of times on GitLab community, I already tried the following things that were suggested but none of them work:

Trying to put /symfony in front (to try to prevent the runner from using /sh)

script:
    - /symfony check:security

Just attempting to echo anything:

script:
    - echo "TEST"

Resetting the entry point to “”:

image:
    name: symfonycorp/cli
    entrypoint: [""]

And then explicitly set the entrypoint:

image:
    name: symfonycorp/cli
    entrypoint: ["/symfony"]  # I think this doesn't have any effect since the image already defines this

Can anyone help me to run an image like this with a predefined entrypoint?
Thanks in advance!