Avoid unnecessary conversions of audio files without extension
This will improve the speed performance of the /rows endpoint.

As we analogously do in the `datasets` library and suggested by @lhoestq, we could infer the file format from the header of the file (magic bytes).

To be done, once this PR is merged:
- #2180
Avoid unnecessary conversions of audio files without extension: This will improve the speed performance of the /rows endpoint.

As we analogously do in the `datasets` library and suggested by @lhoestq, we could infer the file format from the header of the file (magic bytes).

To be done, once this PR is merged:
- #2180