bump ed25519 to pre-release

Author: baloo

ed25519-dalek/Cargo.toml

@@ -27,7 +27,7 @@ features = ["batch", "digest", "hazmat", "pem", "serde"]
 
 [dependencies]
 curve25519-dalek = { version = "=4.2.0-pre", path = "../curve25519-dalek", default-features = false, features = ["digest"] }
-ed25519 = { version = ">=2.2, <2.3", default-features = false }
+ed25519 = { version = "=2.3.0-pre", default-features = false }
 signature = { version = ">=2.0, <2.3", optional = true, default-features = false }
 sha2 = { version = "=0.11.0-pre.3", default-features = false }
 subtle = { version = "2.3.0", default-features = false }