fix missed f-strings

[Borda]

What does this PR do?

Fixes #2657

Before submitting

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• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

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📚 Documentation preview 📚: https://torchmetrics--2667.org.readthedocs.build/en/2667/

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 69%. Comparing base (e702807) to head (9c50291).
Report is 111 commits behind head on master.

Additional details and impacted files

@@          Coverage Diff           @@
##           master   #2667   +/-   ##
======================================
  Coverage      69%     69%           
======================================
  Files         316     316           
  Lines       17881   17881           
======================================
  Hits        12331   12331           
  Misses       5550    5550