fix: remove #![feature(const_raw_ptr_deref)]

`const_raw_ptr_deref` has been stabilized by
<rust-lang/rust#89551>.

src/r3/src/lib.rs

@@ -7,7 +7,6 @@
 #![feature(maybe_uninit_slice)]
 #![feature(const_mut_refs)]
 #![feature(const_slice_from_raw_parts)]
-#![feature(const_raw_ptr_deref)]
 #![feature(const_option)]
 #![feature(const_trait_impl)]
 #![feature(const_refs_to_cell)]

src/r3_kernel/src/lib.rs

@@ -4,7 +4,6 @@
 #![feature(const_fn_fn_ptr_basics)]
 #![feature(cfg_target_has_atomic)] // `#[cfg(target_has_atomic_load_store)]`
 #![feature(const_fn_trait_bound)]
-#![feature(const_raw_ptr_deref)]
 #![feature(exhaustive_patterns)] // `let Ok(()) = Ok::<(), !>(())`
 #![feature(generic_const_exprs)]
 #![feature(const_refs_to_cell)]

src/r3_port_arm/src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(const_mut_refs)]
 #![feature(const_fn_fn_ptr_basics)]
 #![feature(const_ptr_offset_from)]
-#![feature(const_raw_ptr_deref)]
 #![feature(const_refs_to_cell)]
 #![feature(const_trait_impl)]
 #![feature(decl_macro)]

src/r3_port_arm_m/src/lib.rs

@@ -5,7 +5,6 @@
 #![feature(decl_macro)]
 #![feature(generic_const_exprs)]
 #![feature(const_ptr_offset_from)]
-#![feature(const_raw_ptr_deref)]
 #![feature(const_refs_to_cell)]
 #![feature(slice_ptr_len)]
 #![feature(naked_functions)]