once_cell in std from 1.70 (#14402)

* once_cell now stable

* cargo fmt

---------

Co-authored-by: parity-processbot <>

substrate/client/executor/wasmtime/Cargo.toml

@@ -39,7 +39,6 @@ sp-wasm-interface = { version = "14.0.0", path = "../../../primitives/wasm-inter
 # this doesn't have any actual benefits for us besides making it harder to debug memory
 # problems (since then `mmap` etc. cannot be easily hooked into).
 rustix = { version = "0.36.7", default-features = false, features = ["std", "mm", "fs", "param", "use-libc"] }
-once_cell = "1.12.0"
 
 [dev-dependencies]
 wat = "1.0"

substrate/client/executor/wasmtime/src/util.rs

@@ -144,8 +144,8 @@ pub(crate) fn replace_strategy_if_broken(strategy: &mut InstantiationStrategy) {
 		InstantiationStrategy::LegacyInstanceReuse => InstantiationStrategy::RecreateInstance,
 	};
 
-	use once_cell::sync::OnceCell;
-	static IS_OK: OnceCell<bool> = OnceCell::new();
+	use std::sync::OnceLock;
+	static IS_OK: OnceLock<bool> = OnceLock::new();
 
 	let is_ok = IS_OK.get_or_init(|| {
 		let is_ok = match is_madvise_working() {