Compilation Breaks in Latest Nightly

[GuyLewin]

MaybeUninit::uninit_array was removed since it was never in stable (rust-lang/rust#96097).

It's used several times in msgpacker e.g https://github.com/codx-dev/msgpacker/blob/main/msgpacker/src/unpack/common.rs#L100C46-L100C58.

[tehmatt]

#16 fixes this