Audit the `unsafe` call

[Moelf]

AwkwardArray.jl/src/all_implementations.jl

Lines 3462 to 3465 in 095a48b

	unsafe_copyto!(
	reinterpret(Ptr{UInt8}, pointer(mask.chunks)),
	pointer(raw_mask),
	excess_length,

we should try to remove this unsafe call because Julia's built-in Vector now has an underlying Memory{T} construct that may interfere with pointer hacks