Add TRL

[arsalanu]

TODO:

• Add TRL implementation for RL
• TRL currently breaks torchforge dependencies, lots of conflicting packages - mainly vLLM
• Need to alternate RL environment between either building for TRL OR building for torchforge
• Handle dependencies as extensions to core dependencies (torchtune is more mature)
• For TRL: need to handle flash-attn install for cp12/x86/torch2.9 wheel.
• Everything needs to be built with torch 2.9.0, need to fix versions

Small extra:

• Also moves qwen3 handling for torchforge into its own file.