Fix compatibility issues with Python 3.12 and modern library versions

[k2-gc]

Thanks for your great work on this repository!

In this PR, I applied the following modifications to support Python 3.12 and updated dependencies:

• requirements.txt
  Added required libraries with version specifications.

• train.py / val.py

  1. Updated import statements and usage to be compatible with albumentations==2.0.6.
  2. Added logic to use GPU only if available.

• dataset.py
  If self.transform includes Normalize(), skip dividing image pixels by 255.0.

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NOTE:
This modification is not backward compatible and may cause errors when used with older library versions.