Stop using `infra.runATH` (#7397)

* Stop using `infra.runATH`

* Forget execute bit https://github.com/jenkinsci/jenkins/pull/7397#discussion_r1024934609



* Apply suggestions from code review

Co-authored-by: Damien Duportal <damien.duportal@gmail.com>

* More legible to read commands from a here-doc https://github.com/jenkinsci/jenkins/pull/7397#discussion_r1024933518

* May as well split up `run.sh` args by line too

* Spell out Bash options https://github.com/jenkinsci/jenkins/pull/7397#discussion_r1025152483



Co-authored-by: Damien Duportal <damien.duportal@gmail.com>