[Running CI now] Remove duplicate tests to speed up CI (#6768)
* remove tests to speed up CI
* add back _into_data_parallelism tests to see how long the CI test takes
* remove unnecessary save calls
* add back data_parallelism_full_precision_bart_path
* add data_parallelism_full_precision_path
* remove data parallelism tests
Co-authored-by: Jingyan Wang <jingywa@OrtTrainingDev3.af05slrtruoetgaxwwjv5nsq5e.px.internal.cloudapp.net>