Fix conditionals

src/lib.rs

@@ -1,14 +1,13 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 #![allow(stable_features)]
-#![cfg_attr(target_arch = "xtensa", feature(asm_experimental_arch))]
-#![cfg_attr(
-    feature = "nightly",
-    feature(doc_cfg),
-    feature(async_fn_in_trait),
-    feature(impl_trait_projections)
-)]
+#![allow(unknown_lints)]
 #![allow(clippy::unused_unit)] // enumset
 #![warn(clippy::large_futures)]
+#![cfg_attr(feature = "nightly", feature(async_fn_in_trait))]
+#![cfg_attr(feature = "nightly", allow(async_fn_in_trait))]
+#![cfg_attr(feature = "nightly", feature(impl_trait_projections))]
+#![cfg_attr(feature = "nightly", feature(doc_cfg))]
+#![cfg_attr(target_arch = "xtensa", feature(asm_experimental_arch))]
 
 #[cfg(all(not(feature = "riscv-ulp-hal"), not(feature = "esp-idf-sys")))]
 compile_error!("Exactly one of the features `esp-idf-sys` or `riscv-ulp-hal` needs to be enabled");