GarbageCleaner should log pool names, not Python pool object ids

[praiskup]

see strings like: <resallocserver.manager.Pool object at 0x7ff5b9dea5f0>

 INFO 2025-07-21 15:37:41,963 PID:996054:140692659631808(GarbageCleaner-<resallocserver.manager.Pool object at 0x7ff5bbb165f0>) Cleaning unused resources in copr_hv_ppc64le_01_dev pool
 INFO 2025-07-21 15:37:42,024 PID:996054:140692651239104(GarbageCleaner-<resallocserver.manager.Pool object at 0x7ff5b9dea5f0>) Cleaning unused resources in copr_hv_ppc64le_02_dev pool