Sanitize profile filename

[SkafteNicki]

What does this PR do?

Fixes #21365
Make sure that filenames are sanitized when profiler is trying to dump .prof files.
This will currently crash if there are characters such as "/" in the filename, which happens if the user has a ModelCheckpoint with a monitoring metric like "val/acc".

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📚 Documentation preview 📚: https://pytorch-lightning--21395.org.readthedocs.build/en/21395/

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 79%. Comparing base (9ae18f7) to head (13e13fd).
✅ All tests successful. No failed tests found.

❗ There is a different number of reports uploaded between BASE (9ae18f7) and HEAD (13e13fd). Click for more details.

HEAD has 1416 uploads less than BASE

Flag	BASE (9ae18f7)	HEAD (13e13fd)
python3.12.7	96	7
lightning_fabric	89	0
pytest	179	0
cpu	347	28
python3.12	107	9
python3.10	36	3
lightning	168	13
python3.11	72	6
python	36	3
pytorch_lightning	90	15
pytorch2.7	18	3
pytest-full	168	28
pytorch2.1	36	6
pytorch2.2.2	18	3
pytorch2.6	18	3
pytorch2.3	18	3
pytorch2.8	18	3
pytorch2.4.1	12	2
pytorch2.9	18	3
pytorch2.5.1	12	2

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #21395     +/-   ##
=========================================
- Coverage      86%      79%     -8%     
=========================================
  Files         269      266      -3     
  Lines       23809    23761     -48     
=========================================
- Hits        20574    18657   -1917     
- Misses       3235     5104   +1869