update to steel 2.1

Author: robertohuertasm

basics/processing-instructions/steel/Cargo.toml

@@ -17,5 +17,5 @@ processing-instructions-api = { path = "./api", version = "0.1.0" }
 bytemuck = "1.14"
 num_enum = "0.7"
 solana-program = "1.18"
-steel = "1.3"
+steel = "2.1"
 thiserror = "1.0"