update the lower and upper bounds of audio metrics

[quancs]

What does this PR do?

The current lower and upper ploting bounds for audio metrics are incorrect, this PR correct these bounds.

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

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📚 Documentation preview 📚: https://torchmetrics--1786.org.readthedocs.build/en/1786/

[codecov]

Codecov Report

Merging #1786 (b8e01b7) into master (ad61da4) will decrease coverage by 49%.
The diff coverage is 100%.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #1786     +/-   ##
========================================
- Coverage      87%     38%    -49%     
========================================
  Files         254     254             
  Lines       14222   14224      +2     
========================================
- Hits        12324    5335   -6989     
- Misses       1898    8889   +6991