DocumentReferenceManagerImpl: go back to using slower but safer iterInDbChildren (IDEA-CR-55670)

for the unlikely case when someone loads a new child into memory from persistence and creates a doc reference to it just before deletion events are fired

GitOrigin-RevId: dcd9d593bfa29ad6730df20dc9212a4e98b37858

platform/platform-impl/src/com/intellij/openapi/command/impl/DocumentReferenceManagerImpl.java

@@ -87,7 +87,7 @@ public final class DocumentReferenceManagerImpl extends DocumentReferenceManager
       files.add(f);
     }
     else {
-      for (VirtualFile each : ((NewVirtualFile)f).getCachedChildren()) {
+      for (VirtualFile each : ((NewVirtualFile)f).iterInDbChildren()) {
         collectDeletedFiles(each, files);
       }
     }