bump hex-conservative dep from 0.1 to 0.2

It bugs me to have two versions of hex-conservative.

Our lockfile retains hex-conservative 0.1, because our fuzztests depend
on an old released version of this crate.

Author: apoelstra

Cargo-recent.lock

@@ -456,7 +456,7 @@ dependencies = [
  "byteorder",
  "elements",
  "getrandom",
- "hex-conservative 0.1.2",
+ "hex-conservative 0.2.1",
  "miniscript",
  "santiago",
  "serde",

Cargo.toml

@@ -27,7 +27,7 @@ bitcoin-miniscript = { package = "miniscript", version = "12.0.0" }
 byteorder = "1.3"
 elements = { version = "0.25.0", optional = true, default-features = false }
 hashes = { package = "bitcoin_hashes", version = "0.14" }
-hex = { package = "hex-conservative", version = "0.1.1" }
+hex = { package = "hex-conservative", version = "0.2.1" }
 santiago = "1.3"
 simplicity-sys = { version = "0.5.0", path = "./simplicity-sys" }
 serde = { version = "1.0.103", features = ["derive"], optional = true }