Delete src/quacc/calculators/vasp/presets/magmoms_MP.yaml (#2018)

## Summary of Changes

This is available in pmg. 

### Checklist

- [ ] I have read the ["Guidelines"
section](https://quantum-accelerators.github.io/quacc/dev/contributing.html#guidelines)
of the contributing guide. Don't lie! 😉
- [ ] My PR is on a custom branch and is _not_ named `main`.
- [ ] I have added relevant, comprehensive [unit
tests](https://quantum-accelerators.github.io/quacc/dev/contributing.html#unit-tests).

### Notes

- Your PR will likely not be merged without proper and thorough tests.
- If you are an external contributor, you will see a comment from
[@buildbot-princeton](https://github.com/buildbot-princeton). This is
solely for the maintainers.
- When your code is ready for review, ping one of the [active
maintainers](https://quantum-accelerators.github.io/quacc/about/contributors.html#active-maintainers).