[CI] Ensure int16 in wav-diff write-out
- Related issues: None
- Requested reviewers: @kiene
Reason why this change is needed
- The 48kHz out tests are silently failing in BASOP.
Description of the change
- The memory reduction in audioarray.compare removed an explicit cast to int16 for the 48 kHz write-out. This adds it back.
Affected operating points
- Should re-enable all tests with 48kHz output in MLD comparisons in BASOP CI.