[BugFix] Fix compat with pt 2.1.1 (#3157)

Author: vmoens

torchrl/data/replay_buffers/storages.py

@@ -50,7 +50,7 @@
 try:
     from torch.compiler import is_compiling
 except ImportError:
-    from torch._dynamo import is_dynamo_compiling as is_compiling
+    from torch._dynamo import is_compiling
 
 
 class Storage: