[FEATURE] Update MistralLLM to use the client of version 1.0.0

[plaguss]

Is your feature request related to a problem? Please describe.
Mistralai has updated the client and we should update the code to keep up to date.

Describe the solution you'd like
There's a guide for the migration process here,
we should update the async client internally.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.