Revert "Ignore stored GCBarrierPreparation (ydb-platform#7473)"

This reverts commit ccf98e2.

Author: zverevgeny

ydb/core/tx/columnshard/blobs_action/bs/blob_manager.cpp

@@ -140,14 +140,9 @@ bool TBlobManager::LoadState(IBlobManagerDb& db, const TTabletId selfTabletId) {
     if (!db.LoadLastGcBarrier(LastCollectedGenStep)) {
         return false;
     }
-    //https://github.com/ydb-platform/ydb/issues/7468
-    TGenStep storedGCBarrierPreparation;
-    if (!db.LoadGCBarrierPreparation(storedGCBarrierPreparation)) {
+    if (!db.LoadGCBarrierPreparation(GCBarrierPreparation)) {
         return false;
     }
-    if (storedGCBarrierPreparation < LastCollectedGenStep) {
-        AFL_WARN(NKikimrServices::TX_COLUMNSHARD_BLOBS_BS)("mem_genstep", GCBarrierPreparation)("last_genstep", LastCollectedGenStep)("db_genstep", storedGCBarrierPreparation);
-    }
     AFL_VERIFY(!GCBarrierPreparation.Generation() || LastCollectedGenStep <= GCBarrierPreparation)("prepared", GCBarrierPreparation)("last", LastCollectedGenStep);
 
     // Load the keep and delete queues