[9.1] TEST Segregate test methods in ThreadPoolMergeExecutorServiceDiskSpaceTests wrt to the mocked filesystems (#130430)#130524

albertzaharovits merged 1 commit intoelastic:9.1elastic/elasticsearch:9.1from

albertzaharovits:backport-91-segrate_merge_executor_disk_space_testsalbertzaharovits/elasticsearch:backport-91-segrate_merge_executor_disk_space_testsCopy head branch name to clipboard