Changes to Invoke a model with routing

request property messages/items/role was restricted to a list of enum values

the messages request property's minItems was increased to 1

removed the optional property tool_calls from the response with the 200 status

added the new assistant enum value to the request property messages/items/role

added the new system enum value to the request property messages/items/role

added the new user enum value to the request property messages/items/role

added the optional property cache_cost_usd to the response with the 200 status

added the optional property retry_after to the response with the 400 status

added the optional property retry_after to the response with the 401 status

added the optional property retryable to the response with the 400 status

added the optional property retryable to the response with the 401 status

removed the pydantic_tools enum value from the execution_engine response property for the response status 200