Implemented update function in cache_utils.py, with a test file test_cache_utils.py 
Author: ailunc
Pull request: yes

# What does this PR do?
Implemented update function in cache_utils.py, with a test file test_cache_utils.py
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Fixes # (issue)https://github.com/huggingface/transformers/issues/37078

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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      to it if that's the case. https://github.com/huggingface/transformers/issues/37078
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cc @gante here and the original issue at #37078