The properties is for "retries" which you should be able to disable with a count of zero. but you can not. but the comment implies it is just for the number of tries (not retries).
However the code calls PathRemover.newFilteredRobustRemover(pathChecker, DELETION_MAX - 1, GC_AFTER_FAILED_DELETE, WAIT_BETWEEN_DELETION_RETRIES);]
which ends up in https://github.com/jenkinsci/jenkins/blob/c8efc7c78e26f3aefad24ef4c8a161cb9a269ea3/core/src/main/java/jenkins/util/io/PathRemover.java#L63-L65 which is using a max retries.
However if you run a test with the system property set to one. then you do get one retry not one try.
so the property does seem to be acting as a retry despite the code comment but you can not set it to zero one because...
and the PathRemover]..
which means it will always retry once, which is a PITA when trying to some timing bugs.