Add no_std for peg crate

[A4-Tacks]

No description provided.

[A4-Tacks]

use cargo test --target aarch64-unknown-none

error[E0463]: can't find crate for `std`
  |
  = note: the `aarch64-unknown-none` target may not support the standard library
  = note: `std` is required by `peg` because it does not declare `#![no_std]`

For more information about this error, try `rustc --explain E0463`.
error: could not compile `peg` (lib) due to 1 previous error