enable xla fsdp (#32048)

* enable xla fsdp

* add acceleration version check for xla fsdp

src/transformers/training_args.py

@@ -1902,7 +1902,7 @@ class TrainingArguments:
                 warnings.warn("`--xla_fsdp_grad_ckpt` is useful only when `--xla` is set to true.")
 
         # accelerate integration for FSDP
-        if len(self.fsdp) > 0 and not self.fsdp_config["xla"]:
+        if len(self.fsdp) > 0 and is_accelerate_available("0.28.0"):
             os.environ["ACCELERATE_USE_FSDP"] = "true"
             from accelerate.utils.constants import (
                 FSDP_AUTO_WRAP_POLICY,