Fix chat CLI GPU loading and request_id validation issues (#40230) (#40232)
* Fix chat CLI GPU loading and request_id validation issues (#40230)
This commit addresses two critical bugs in the transformers chat CLI:
1. **GPU Loading Issue**: Changed default device from "cpu" to "auto" in ChatArguments
- Chat CLI now automatically uses GPU when available instead of defaulting to CPU
- Matches the behavior of the underlying serving infrastructure
2. **Request ID Validation Error**: Added request_id field to TransformersCompletionCreateParamsStreaming schema
- Fixes "Unexpected keys in the request: {'request_id'}" error on second message
- Allows request_id to be properly sent and validated by the server
Both fixes target the exact root causes identified in issue #40230:
- Users will now get GPU acceleration by default when available
- Chat sessions will no longer break after the second message
* Remove unrelated request_id field from TransformersCompletionCreateParamsStreaming