In MDL-68969, we moved most of the code that is used to test the mobile application into moodle-local_moodleappbehat. However, the old code is still in Moodle core and I'd consider that dead code, so we should remove it to clean up.

Other than that, I noticed there is some code to run the ionic application from Moodle using $CFG->behat_ionic_dirroot. I'm not sure in which situations that was useful, but I think we should remove it as well because it's also something that may change in the app and the recommended way is to launch the app elsewhere (either manually or using moodle-docker).