Remove unnecssary rand-std flag

Author: nyonson

Cargo.toml

@@ -20,7 +20,6 @@ rustdoc-args = ["--cfg", "docsrs"]
 default = ["std"]
 std = ["bitcoin/std", "bitcoin-internals/std", "miniscript?/std"]
 rand = ["bitcoin/rand"]
-rand-std = ["bitcoin/rand-std"]
 serde = ["dep:actual-serde", "bitcoin/serde", "bitcoin-internals/serde"]
 base64 = ["bitcoin/base64"]
 miniscript = ["dep:miniscript", "miniscript?/no-std"]