Release v2.9.1

feat: Adding webp to image assets for downloading (#201)

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This PR updates the `_send_http_request` function in the
`cohere_compass/clients/compass.py` and
`cohere_compass/clients/compass_async.py` files.

- The function now checks for the `image/webp` content type in addition
to `image/jpeg` and `image/png`.
- This change ensures that the function can handle responses from
`get_document_asset()` when the asset is an image in WebP format.

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