With grails-geb 4.1.x (Grails 6), 4.2.x (Grails 6) and 5.0.x (Grails 7) you will need to have a local container environment.

https://github.com/apache/grails-geb?tab=readme-ov-file#containergebspec-recommended

This change was made due to to old web driver solution no longer be maintained.

https://github.com/erdi/webdriver-binaries-gradle-plugin/pull/44