build(deps): bump secp256k1 from 0.20.0 to 0.20.1

Bumps [secp256k1](https://github.com/rust-bitcoin/rust-secp256k1) from 0.20.0 to 0.20.1.
- [Release notes](https://github.com/rust-bitcoin/rust-secp256k1/releases)
- [Changelog](https://github.com/rust-bitcoin/rust-secp256k1/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rust-bitcoin/rust-secp256k1/commits)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Cargo.lock

@@ -27,7 +27,7 @@ lazy_static = "1.4.0"
 primitive-types = "0.8.0"
 rand_core = "0.5.1"
 ripemd160 = "0.8.0"
-secp256k1 = { version = "0.20.0", features = ["serde"] }
+secp256k1 = { version = "0.20.1", features = ["serde"] }
 serde = { version = "1", features = ["serde_derive", "rc"] }
 serde-big-array = "0.3.1"
 sha2 = { version = "0.9.2", features=["compress"] }