Upgrade PyMongo to >=4.13.0 and enable async client (AsyncMongoClient)

[DylanWelzel]

Upgrade our MongoDB driver dependency to at least 4.13.0 so we can adopt PyMongo’s stabilized AsyncMongoClient.

In May 2025 they released the 4.13.0 pymongo where the asynchronous api became stable and they depreciated the motor driver.