CI started reporting warnings about including `bytes.hh` in
several files. The reason is they actually only use code
introduced in `bytes_fwd.hh` (which is also included by `bytes.hh`).
Clang-include-cleaner suggests that we get rid of that indirection
and only include `bytes_fwd.hh`. That's what happens in this commit.
We include `bytes.hh` in `exceptions/exceptions.cc` because
it relies on the formatting utilities declared and defined
in `bytes.hh`.
Closesscylladb/scylladb#20842
7a7a1e3558