Update Cargo.toml (#178)

Bumps the dependency to at least 4.1.3 as per the advisory:

https://rustsec.org/advisories/RUSTSEC-2024-0344.html

(even though this crate may not be using the function mentioned in the
advisory, it is better to bump it to ensure that there is no chance of
other dependencies pulling it)

spake2/Cargo.toml

@@ -15,7 +15,7 @@ edition = "2021"
 rust-version = "1.60"
 
 [dependencies]
-curve25519-dalek = { version = "4", default-features = false, features = ["rand_core"] }
+curve25519-dalek = { version = "4.1.3", default-features = false, features = ["rand_core"] }
 rand_core = { version = "0.6", default-features = false }
 sha2 = { version = "0.10", default-features = false }
 hkdf = { version = "0.12", default-features = false }