Revert "enhance: reduce many I/O operations while loading disk index
(#30189) (#30690)" This reverts commit
d4c4bf946b15bc537acd170dfd1d938bea237c7a.
Revert "enhance: limit the max pool size to 16 (#30371) (#30415)" This
reverts commit 52ac0718f059d4aa45c5908ec8507e6045b24e1f.
Revert "enhance: convert the `GetObject` util to async (#30166)
(#30197)" This reverts commit 4b7c5baab773366aa8084762e7321130c4f894b7.
Signed-off-by: zhenshan.cao <zhenshan.cao@zilliz.com>