atomic_ref<char> in inline void* atomic_load_per_byte_memcpy should be a atomic_ref<const char>

[lbckmnn]

Hey timur,
I stumbled across your implementation of a seqlock and looked into the bytewise atomic memcpy because I need something similar:

crill/include/crill/bytewise_atomic_memcpy.h

Line 45 in 96d67ed

dest_bytes[i] = std::atomic_ref<char>(src_bytes[i]).load(std::memory_order_relaxed);

This does not seem to compile (https://godbolt.org/z/Pa5qjKb3T).
The atomic_ref<char> requires a (non-const) reference.
However, an atomic_ref<const char> seems to be fine in that particular place.