improve the ci to allow adding new config

[renanfranca]

• Fix https://github.com/jhipster/jhipster-lite/issues/11341

The last commit is only to prove that it works: test: create new app testapp in generate.sh and add it to matrix at github-actions.yml

[renanfranca]

It works 😃😃😃

https://github.com/jhipster/jhipster-lite/actions/runs/11801346794/job/32874925871

I am going to remove the test commit as soon as possible 👍

[renanfranca]

@pascalgrimaud : it is ready to review 👍

[pascalgrimaud]

let's try it