Imprinted geometry has more parts than original geometry

While imprinting a cad geometry I notice the number of imprinted parts is larger than the number of parts in the original geometry

we have 5 parts in the original step file and 9 in the imprinted geometry

step file and python script attached that reproduces the issue

I would have exspected the imprinted geometry to also have 5 parts like the original

[oktavian_a_info.zip](https://github.com/user-attachments/files/19450896/oktavian_a_info.zip)

```python
import cadquery as cq

parts = cq.importers.importStep("oktavian_a_info.step").val()

assembly = cq.Assembly()
for part in parts:
print('orignal part', part)
assembly.add(part)

imprinted_assembly, imprinted_solids_with_org_id = cq.occ_impl.assembly.imprint(assembly)
print()

for ipart in imprinted_assembly:
print('imprinted part', ipart)
```

tagging @eepeterson @SteSeg @shimwell