`transmute<&mut [MaybeUninit<T>], &mut [T]>` is unsound due to Rust doc!

[bczhc]

https://github.com/bczhc/bzip3-rs/blob/4435d3a6c8fb7b33cb46049268383f9dc5a3e613/src/lib.rs#L92-L94

[bczhc]

• https://doc.rust-lang.org/nightly/std/io/trait.Read.html#tymethod.read

  Calling read with an uninitialized buf (of the kind one obtains via MaybeUninit) is not safe, and can lead to undefined behavior.

• https://stackoverflow.com/questions/70220906/why-do-readread-and-readread-exact-require-that-the-buffers-passed-to-them-b

• https://users.rust-lang.org/t/proper-way-write-to-maybeuninit-u8-const-via-mut-u8