fix: remove primitive-types/serde feature to avoid getrandom on wasm32

The serde feature was enabling primitive-types/serde which transitively
enables std -> fixed-hash/std -> rand/std -> getrandom. This fails on
wasm32-unknown-unknown target. Using only primitive-types/serde_no_std
provides serde support without the std dependency chain.

bizinikiwi/primitives/core/Cargo.toml

@@ -152,7 +152,6 @@ serde = [
 	"log/serde",
 	"parking_lot?/serde",
 	"pezsp-storage/serde",
-	"primitive-types/serde",
 	"primitive-types/serde_no_std",
 	"rand?/serde",
 	"scale-info/serde",