[Assistants] Default model settings (Temp, Top K, Top P) do not work on Anthropic models

[gururise]

Steps to reproduce:

1. Set up a new Assistant and select an Anthropic model
   

2. Leave Temp, Top K, Top P as defaults. Try to use the newly created assistant:
   

The error message "Temperature should be a valid number" appears and the model is unusable. If you manually set the temperature in the Assistant settings, it will complain about Top P and Top K not being a number. If you manually set those three settings, the assistant will then work.