Ci/update basop ci branch

• Related issues: None
• Requested reviewers:

Reason why this change is needed

• Test with non 48kHz output may fail in the BASOP CI. This should fix it.

Description of the change

• Explicitly set int16 format for files already in 48 kHz.

Affected operating points

• Affects all tests with 48kHz output SR in BASOP CI.