Remove MPS config for specific datafetching test

[justusschock]

🐛 Bug

https://github.com/Lightning-AI/lightning/blob/master/tests/tests_pytorch/utilities/test_fetching.py#L198

Runs on both cuda on mps but tests a cuda-specific feature built on cuda-streams with frequent calls to cuda. This test was failing in #14368 .

I suggest to remove the mps config for this test entirely as it does not make sense!

I did not add this to #14012 as we shouldn't figure out what to properly mock here but just remove the configuration.

cc @Borda @akihironitta @justusschock @awaelchli @carmocca