update docs, no torchdata anymore

docs/getting_started/installation.rst

@@ -17,7 +17,7 @@ and you also might want to add the option :code:`--user`
 (if you are not using ``virtualenv``).
 
 For TensorFlow, use :code:`pip install tensorflow`,
-and for PyTorch, use :code:`pip install torch torchdata torchaudio`.
+and for PyTorch, use :code:`pip install torch torchaudio`.
 
 For some specific datasets or special layers, additional dependencies might be needed,
 such as ``librosa``.

returnn/torch/data/pipeline.py

@@ -1,7 +1,8 @@
 """
 Code to create PyTorch datasets that can be used with the PyTorch DataLoader.
 
-We make use of TorchData data pipelines.
+We make use of torch.utils.data.IterDataPipe data pipelines.
+(We used TorchData before but migrated back to pure PyTorch. https://github.com/rwth-i6/returnn/issues/1382)
 
 Most functionality is implemented as a dataset/datapipe, as this seems to be the common way in PyTorch,
 as it is also commonly done in Fairseq:

returnn/torch/data/returnn_dataset_wrapper.py

@@ -1,7 +1,7 @@
 """
 Wrapper for RETURNN datasets.
 
-We make use of TorchData data pipelines.
+We make use of torch.utils.data.IterDataPipe.
 """
 
 from __future__ import annotations