Remove redundant feature attribure; once_cell will be stabilized since 1.70.

Author: falsetru

src/lib.rs

@@ -1,7 +1,6 @@
 #![feature(maybe_uninit_slice)]
 #![feature(maybe_uninit_uninit_array)]
 #![feature(maybe_uninit_array_assume_init)]
-#![feature(once_cell)]
 #![feature(alloc_error_handler)]
 #![cfg_attr(not(test), no_std)]
 extern crate alloc;

src/main.rs

@@ -1,7 +1,6 @@
 #![feature(maybe_uninit_uninit_array)]
 #![feature(maybe_uninit_slice)]
 #![feature(maybe_uninit_array_assume_init)]
-#![feature(once_cell)]
 #![feature(alloc_error_handler)]
 #![no_builtins]
 #![no_std]