Remove deprecated codes (#24837)

* remove `xpu_backend` training argument

* always call `contextlib.nullcontext()` since transformers updated to
python3.8

* these codes will not be executed

src/transformers/trainer.py

@@ -629,20 +629,7 @@ class Trainer:
                     #  bf16 does not need grad scaling
                     self.do_grad_scaling = self.amp_dtype == torch.float16
                     if self.do_grad_scaling:
-                        if self.sharded_ddp is not None:
-                            self.scaler = ShardedGradScaler()
-                        elif self.fsdp is not None:
-                            from torch.distributed.fsdp.sharded_grad_scaler import (
-                                ShardedGradScaler as FSDPShardedGradScaler,
-                            )
-
-                            self.scaler = FSDPShardedGradScaler()
-                        elif is_torch_tpu_available():
-                            from torch_xla.amp import GradScaler
-
-                            self.scaler = GradScaler()
-                        else:
-                            self.scaler = torch.cuda.amp.GradScaler()
+                        self.scaler = ShardedGradScaler()
                 elif args.half_precision_backend == "cpu_amp":
                     self.use_cpu_amp = True
                     self.amp_dtype = torch.bfloat16
@@ -2621,7 +2608,7 @@ class Trainer:
                 else torch.cuda.amp.autocast(cache_enabled=cache_enabled, dtype=self.amp_dtype)
             )
         else:
-            ctx_manager = contextlib.nullcontext() if sys.version_info >= (3, 7) else contextlib.suppress()
+            ctx_manager = contextlib.nullcontext()
 
         return ctx_manager
 

src/transformers/training_args.py

@@ -1189,14 +1189,6 @@ class TrainingArguments:
         },
     )
 
-    xpu_backend: Optional[str] = field(
-        default=None,
-        metadata={
-            "help": "The backend to be used for distributed training on Intel XPU.",
-            "choices": ["mpi", "ccl", "gloo"],
-        },
-    )
-
     def __post_init__(self):
         # expand paths, if not os.makedirs("~/bar") will make directory
         # in the current directory instead of the actual home
@@ -1220,14 +1212,6 @@ class TrainingArguments:
             # Go back to the underlying string or we won't be able to instantiate `IntervalStrategy` on it.
             self.evaluation_strategy = self.evaluation_strategy.value
 
-        if self.xpu_backend is not None:
-            warnings.warn(
-                "using `xpu_backend` is deprecated and will be removed in version 4.31"
-                " of 🤗 Transformers. Use `ddp_backend` instead",
-                FutureWarning,
-            )
-            self.ddp_backend = self.xpu_backend
-
         self.evaluation_strategy = IntervalStrategy(self.evaluation_strategy)
         self.logging_strategy = IntervalStrategy(self.logging_strategy)
         self.save_strategy = IntervalStrategy(self.save_strategy)