chore: remove ctor (#1168)

crates/cdk-ffi/Cargo.toml

@@ -18,7 +18,6 @@ bip39 = { workspace = true }
 cdk = { workspace = true, default-features = false, features = ["wallet", "auth", "bip353"] }
 cdk-sqlite = { workspace = true }
 cdk-postgres = { workspace = true, optional = true }
-ctor = "0.2"
 futures = { workspace = true }
 once_cell = { workspace = true }
 rand = { workspace = true }