remove unused lint cfg causing warning

Author: RCasatta

Cargo.toml

@@ -35,9 +35,6 @@ bitcoin = { version = "0.32.0", features = ["base64"] }
 secp256k1 = { version = "0.29.0", features = ["rand-std"] }
 actual-base64 = { package = "base64", version = "0.13.0" }
 
-[lints.rust]
-unexpected_cfgs = { level = "deny", check-cfg = ['cfg(miniscript_bench)'] }
-
 [[example]]
 name = "htlc"
 required-features = ["compiler"]