SP dataloader patching + removing custom sampler / dataloader logic (#2686)

* utilize accelerate prepare_data_loader with patching

* lint

* cleanup, fix

* update to support DPO quirk

* small change

* coderabbit commits, cleanup, remove dead code

* quarto fix

* patch fix

* review comments

* moving monkeypatch up one level

* fix

_quarto.yml

@@ -60,7 +60,6 @@ quartodoc:
         - core.trainers.mixins.optimizer
         - core.trainers.mixins.rng_state_loader
         - core.trainers.mixins.scheduler
-        - core.trainers.mixins.sequence_parallel
     - title: Context Managers
       desc: Context managers for altering trainer behaviors
       contents: