Fix unfixed naming inconsistencies

[XianzheMa]

It turns out my last PR didn't rename all the variables completely, thereby causing CI failures. This PR fixes it.

[MaxiBoether]

When CI runs through feel free to merge

[codecov]

Codecov Report

Attention: Patch coverage is 85.71429% with 1 line in your changes missing coverage. Please review.

Project coverage is 82.49%. Comparing base (84dac1d) to head (4655326).
Report is 2 commits behind head on main.

Files	Patch %	Lines
...trainer_server/internal/trainer/pytorch_trainer.py	85.71%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #531      +/-   ##
==========================================
+ Coverage   82.44%   82.49%   +0.04%     
==========================================
  Files         214      215       +1     
  Lines       10042    10053      +11     
==========================================
+ Hits         8279     8293      +14     
+ Misses       1763     1760       -3     

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[github-actions]

^{( % to main)
( % to main)}

[robinholzi]

what a PR title xD