Release v1.9.0

feat: Increase max accepted file size to 500mb (#155)

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This PR updates the file size limit in the
`cohere_compass/clients/parser.py` file.

- `DEFAULT_MAX_ACCEPTED_FILE_SIZE_BYTES` is increased from 50,000,000 to
500,000,000.
- `max_size_mb` is calculated using integer division (`//`) instead of
float division (`/`).
- The error message is updated to use uppercase "MB" instead of
lowercase "mb".

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