Investigate switching type tests to Vitest

[EskiMojo14]

Vitest provides its own suite for testing types, which would be good to switch our tests over to.

We need to make sure we can get the same checks and safety, but it looks like toEqualTypeOf is equivalent to expectExactType and toMatchTypeOf is equivalent to expectType.

[aryaemami59]

From my experience toEqualTypeOf and expectExactType don't seem to be 100% interchanchable. toEqualTypeOf seems to be slightly more strict/accurate than expectExactType but I could be wrong. I can go ahead and get started on the conversion.

[EskiMojo14]

I think stricter is okay - less strict would be bad