Companion: wasm-builder support stable Rust (#6967)

* Companion: wasm-builder support stable Rust

* update lockfile for {"substrate"}

---------

Co-authored-by: parity-processbot <>

polkadot/parachain/test-parachains/undying/src/lib.rs

@@ -17,10 +17,6 @@
 //! Basic parachain that adds a number as part of its state.
 
 #![no_std]
-#![cfg_attr(
-	not(feature = "std"),
-	feature(core_intrinsics, lang_items, core_panic_info, alloc_error_handler)
-)]
 
 use parity_scale_codec::{Decode, Encode};
 use sp_std::vec::Vec;