Remove nightly and unstable-traits features in preparation for 1.75.

embassy-boot/boot/src/test_flash/blocking.rs

@@ -51,7 +51,6 @@ where
     }
 }
 
-#[cfg(feature = "nightly")]
 impl<ACTIVE, DFU, STATE> BlockingTestFlash<ACTIVE, DFU, STATE>
 where
     ACTIVE: NorFlash + embedded_storage_async::nor_flash::NorFlash,

embassy-boot/boot/src/test_flash/mod.rs

@@ -1,7 +1,5 @@
-#[cfg(feature = "nightly")]
 mod asynch;
 mod blocking;
 
-#[cfg(feature = "nightly")]
 pub(crate) use asynch::AsyncTestFlash;
 pub(crate) use blocking::BlockingTestFlash;