fix for MetricCollection.update gives identical results

[rbedyakin]

What does this PR do?

Fixes #2916

Before submitting

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• Did you make sure to update the docs?
• Did you write any new necessary tests?

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📚 Documentation preview 📚: https://torchmetrics--2944.org.readthedocs.build/en/2944/

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.

Project coverage is 70%. Comparing base (2ffcedf) to head (334ea90).

Additional details and impacted files

@@          Coverage Diff           @@
##           master   #2944   +/-   ##
======================================
- Coverage      70%     70%   -0%     
======================================
  Files         332     332           
  Lines       18996   18998    +2     
======================================
  Hits        13253   13253           
- Misses       5743    5745    +2