`std::thread::park` is a better suggestion for fixing `clippy::empty_loop`

Description

I got the following warning:

warning: empty `loop {}` wastes CPU cycles
   --> src/sequences/fibonacci.rs:717:18
    |
717 |             _ => loop {},
    |                  ^^^^^^^
    |
    = help: you should either use `panic!()` or add `std::thread::sleep(..);` to the loop body
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_loop
    = note: `#[warn(clippy::empty_loop)]` on by default

It would be better to instead suggest or to also suggest std::thread::park() when the loop is supposed to truly do nothing, which uses even less CPU cycles than sleeping or yielding does. If this suggestion is accepted, changing the suggestions at https://rust-lang.github.io/rust-clippy/master/index.html#empty_loop would be needed as well.

Version

rustc 1.71.1 (eb26296b5 2023-08-03)
binary: rustc
commit-hash: eb26296b556cef10fb713a38f3d16b9886080f26
commit-date: 2023-08-03
host: x86_64-unknown-linux-gnu
release: 1.71.1
LLVM version: 16.0.5

Additional Labels

No response

Start at the clippy::empty_loop lint entry point and compare its current help text with the requested std:🧵:park alternative. Check the linked empty_loop documentation as well; done means the diagnostic and documented suggestions consistently explain the accepted alternative without wasting CPU cycles.