Migrate to TS 5

[Raiden1411]

Since viem recently migrated to TS 5 and NodeNext, I was wondering if it would make sense to do the same here.

What do you think @tmm?

[tmm]

Definitely! Would be great if abitype's build and typechecking set up was the same.

Probably want to wait on using some TypeScript v5 backwards incompatible features (like const type parameters) until viem and wagmi's minimum versions are bumped to v5 as well.

[Raiden1411]

Agreed. For now the focus will just be updating the typechecking and build. The rest will come in due time once everything is ready