Fix inconsistency when user specifies weights_save_path

[daniellepintz]

What does this PR do?

Fixes #12254

Does your PR introduce any breaking changes? If yes, please list them.

When user provides weights_save_path:

• Changed checkpoints save path in the case of one logger from weights_save_path/name/version/checkpoints to weights_save_path/checkpoints
• Changed checkpoints save path in the case of multiple loggers from weights_save_path/name1_name2/version1_version2/checkpoints to weights_save_path/checkpoints

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[tchaton]

LGTM ! Neat !

[codecov]

Codecov Report

Merging #12372 (037cee7) into master (2ee187e) will decrease coverage by 5%.
The diff coverage is 100%.

❗ Current head 037cee7 differs from pull request most recent head d6bcf99. Consider uploading reports for the commit d6bcf99 to get more accurate results

@@           Coverage Diff            @@
##           master   #12372    +/-   ##
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- Coverage      92%      87%    -5%     
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  Files         215      215            
  Lines       18075    18065    -10     
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- Hits        16570    15734   -836     
- Misses       1505     2331   +826     

[daniellepintz]

Could someone please enable auto merge on this?