Update parity-scale-codec to prepare for breaking rustc release (#6746)

This updates parity-scale-codec{-derive} to prepare for a rustc release
that would otherwise break the derive implementation:
rust-lang/rust#73084

Cargo.toml

@@ -12,7 +12,7 @@ description = "Consensus extension module for BABE consensus. Collects on-chain
 targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
-codec = { package = "parity-scale-codec", version = "1.3.1", default-features = false, features = ["derive"] }
+codec = { package = "parity-scale-codec", version = "1.3.4", default-features = false, features = ["derive"] }
 frame-benchmarking = { version = "2.0.0-rc5", default-features = false, path = "../benchmarking", optional = true }
 frame-support = { version = "2.0.0-rc5", default-features = false, path = "../support" }
 frame-system = { version = "2.0.0-rc5", default-features = false, path = "../system" }