Fix: Make WandbLogger upload models from all ModelCheckpoint callbacks, not just one

[cgebbe]

What does this PR do?

• Given a trainer with wandb logger and log_model=True
• and two ModelCheckpoint callbacks
• When training
• Then only models from one checkpoint are uploaded to wandb.

Two questions

• how shall I add CHANGELOG entry?
• do you want this e.g. squashed in one commit?

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• Did you make sure to update the documentation with your changes? (if necessary)
• Did you write any new necessary tests? (not for typos and docs) - yes
• Did you verify new and existing tests pass locally with your changes?
• Did you list all the breaking changes introduced by this pull request?
• Did you update the CHANGELOG? (not for typos, docs, test updates, or minor internal changes/refactors)

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📚 Documentation preview 📚: https://pytorch-lightning--20191.org.readthedocs.build/en/20191/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79%. Comparing base (96df8c4) to head (09097ee).
Report is 115 commits behind head on master.

❗ There is a different number of reports uploaded between BASE (96df8c4) and HEAD (09097ee). Click for more details.

HEAD has 105 uploads less than BASE

Flag	BASE (96df8c4)	HEAD (09097ee)
cpu	48	24
python	6	3
lightning_fabric	11	0
pytest	27	0
lightning	31	15
python3.11	12	6
python3.10	12	6
python3.12.7	18	9
gpu	3	0

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #20191     +/-   ##
=========================================
- Coverage      88%      79%     -9%     
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  Files         267      264      -3     
  Lines       23355    23301     -54     
=========================================
- Hits        20458    18348   -2110     
- Misses       2897     4953   +2056