x448: Cargo.toml fixup (#1744)

Having the dependency broken apart onto multiple lines like this was
breaking the regex that looks for the version in Cargo.toml for Trusted
Publishing

Author: tarcieri

x448/Cargo.toml

@@ -15,15 +15,11 @@ description = "Pure Rust implementation of X448, an elliptic curve Diffie-Hellma
 
 [dependencies]
 ed448-goldilocks = { version = "0.14.0-pre.12", default-features = false }
+zeroize = { version = "1", default-features = false, features = ["zeroize_derive"] }
 
 # optional dependencies
 serdect = { version = "0.4", optional = true }
 
-[dependencies.zeroize]
-version = "1"
-default-features = false
-features = ["zeroize_derive"]
-
 [features]
 default = ["getrandom"]
 getrandom = ["ed448-goldilocks/getrandom"]