!fixup revert the accidental cargo change

Author: dmkozh

soroban-spec-rust/Cargo.toml

@@ -11,7 +11,7 @@ edition = "2021"
 rust-version.workspace = true
 
 [dependencies]
-stellar-xdr = { workspace = true, features = ["next", "std", "serde"] }
+stellar-xdr = { workspace = true, features = ["curr", "std", "serde"] }
 soroban-spec = { workspace = true }
 thiserror = "1.0.32"
 syn = {version="2.0",features=["full"]}
@@ -22,4 +22,3 @@ prettyplease = "0.2.4"
 
 [dev-dependencies]
 pretty_assertions = "1.2.1"
-