[8.19] TEST Segregate test methods in ThreadPoolMergeExecutorServiceDiskSpaceTests wrt to the mocked filesystems (#130430)#130522

elasticsearchmachine merged 2 commits intoelastic:8.19elastic/elasticsearch:8.19from

albertzaharovits:backport-819-segrate_merge_executor_disk_space_testsalbertzaharovits/elasticsearch:backport-819-segrate_merge_executor_disk_space_testsCopy head branch name to clipboard