Add counters for dataset classes
Author: jiangyukunok
Pull request: yes

# What does this PR do?

This improves the logging in **examples/pytorch/text-classification/run_glue.py** by adding counts for different labels in train/validation/test datasets. The logs could be useful when working with classification tasks (spot class imbalance early, check data split consistency, etc).

test result:
04/20/2025 03:52:36 - INFO - __main__ - Class distribution in train set:
04/20/2025 03:52:36 - INFO - __main__ -   Label 1: 2474 (67.45%)
04/20/2025 03:52:36 - INFO - __main__ -   Label 0: 1194 (32.55%)
04/20/2025 03:52:36 - INFO - __main__ - Class distribution in validation set:
04/20/2025 03:52:36 - INFO - __main__ -   Label 1: 279 (68.38%)
04/20/2025 03:52:36 - INFO - __main__ -   Label 0: 129 (31.62%)
04/20/2025 03:52:36 - INFO - __main__ - Class distribution in test set:
04/20/2025 03:52:36 - INFO - __main__ -   Label 1: 1147 (66.49%)
04/20/2025 03:52:36 - INFO - __main__ -   Label 0: 578 (33.51%)


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Hi @ArthurZucker — just checking in to see if you had a chance to review this PR 🙏 
Matt already approved, let me know if any changes are needed!

This is simple enough that we don't need core maintainer approval, don't worry! Thank you for the PR