Mark obsolete methods as obsolete

[Hertzole]

This PR marks some 2D physics calls as obsolete, as they have been obsoleted by Unity. Most NonAlloc calls were obsoleted in 2023.1. GetRayIntersectionNonAlloc seems to have been obsoleted in Unity 6. Confusingly, one GetRayIntersectionNonAlloc and one RaycastNonAlloc method have not been marked as obsolete, so I skipped them. It's not that I missed them.

There are no longer any obsolete warnings when compiling the package, and I confirmed that there are no warnings when building either.

This is my last PR now. I swear I'm not an AI. Just a passionate human haha