fixup! io: Update defmt to 1.0, rename feature from "defmt_03" to "defmt"

Author: chrysn

embedded-io/src/lib.rs

@@ -5,10 +5,6 @@
 
 use core::fmt;
 
-// Note that defmt macros depend on this being named "defmt" precisely, since they emit code that does `defmt::blahblah`.
-#[cfg(feature = "defmt")]
-use defmt;
-
 #[cfg(feature = "alloc")]
 extern crate alloc;