Move ORPOTrainer to trl.experimental #4465
Description
Context
Part of #4223 and #4374 - Moving trainers to experimental submodule for V1.
Task
Move ORPOTrainer from main trl module to trl.experimental:
- Move trainer file to trl/experimental/
- Update imports in init.py files
- Update documentation
- Add deprecation warning in old location
- Update tests
- Verify examples still work
Post-V1 Plan
May stay in trl.experimental.
Related
- Parent tracking issue: Road to v1 #4374
- RFC: [RFC] Moving Most TRL Trainers to the experimental Submodule to Streamline the Core #4223
- BCO migration (completed): 🚚 Move BCO to
trl.experimental#4312