"Import failed..." error and new accumulating entities are created when Reimporting a Sub Scene a few times

Steps to reproduce:

1. Create a new 3D URP project
2. Install Entities package (com.unity.entities)
3. In the Hierarchy, right-click > New Sub Scene > Empty Scene and save it
4. Select it In Hierarchy and click "Close" on the Sub Scene Component in the Inspector
5. Fully expand Sub Scene under Editor World
6. Select the Sub Scene in normal Hierarchy (not under Editor World)
7. In the Inspector, click "Close"
8. Click "Reimport" a few times
9. Observe the Console and "Entity(X:1)" entries under Sub Scene

Actual results: Each reimport creates new entities with new, higher indices (from Entities(1:1) to Entities (10:1) or however times Reimport is pressed) and "Import failed with status Status: SourceDataChangedDuringImport: " error is sometimes thrown

Expected results: Reimporting a SubScene should not create new Entity entries under Sub Scene and no error should be thrown

Reproducible with versions: 6000.6.0b1, 6000.6.0b6,

Not reproducible with versions: 6000.5.6f1, 6000.6.0a7, 6000.7.0a3

Tested on (OS): macOS 26.5, Ubuntu 24.04

Notes:

• Entering Play mode clears invalid Entities