Revert "Add workaround for rust-lang/rust#128617"

This reverts commit b3e9cc7.

Author: datdenkikniet

src/mac/miim.rs

@@ -123,8 +123,6 @@ where
 mod pin_impls {
     use crate::hal::gpio::{gpioa::PA2, gpioc::PC1, Alternate};
 
-    // See: https://github.com/rust-lang/rust/issues/128617
-    #[allow(dead_code)]
     const AF11: u8 = 11;
 
     unsafe impl super::MdioPin for PA2<Alternate<AF11>> {}
@@ -135,8 +133,6 @@ mod pin_impls {
 mod pin_impls {
     use crate::hal::gpio::{gpioa::PA2, gpioc::PC1, Alternate};
 
-    // See: https://github.com/rust-lang/rust/issues/128617
-    #[allow(dead_code)]
     const AF11: u8 = 11;
 
     unsafe impl super::MdioPin for PA2<Alternate<AF11>> {}