Include off-chain dependency only when necessary

crates/storage/Cargo.toml

@@ -27,6 +27,7 @@ scale-info = { version = "1.0", default-features = false, features = ["derive"],
 cfg-if = "1.0"
 array-init = { version = "2.0", default-features = false }
 
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 # Workaround: we actually just need criterion as a dev-dependency, but
 # there is an issue with a doubly included std lib when executing
 # `cargo check --no-default-features --target wasm32-unknown-unknown`.