build(deps): bump secp256k1 from 0.30.0 to 0.31.1

Bumps [secp256k1](https://github.com/rust-bitcoin/rust-secp256k1) from 0.30.0 to 0.31.1.
- [Changelog](https://github.com/rust-bitcoin/rust-secp256k1/blob/master/CHANGELOG.md)
- [Commits](rust-bitcoin/rust-secp256k1@secp256k1-0.30.0...secp256k1-0.31.1)

---
updated-dependencies:
- dependency-name: secp256k1
  dependency-version: 0.31.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Cargo.lock

@@ -63,7 +63,7 @@ scale-decode = { version = "0.16.0", default-features = false }
 scale-encode = { version = "0.10.0", default-features = false }
 scale-info = { version = "2.11", default-features = false }
 schemars = { version = "0.8" }
-secp256k1 = { version = "0.30.0" }
+secp256k1 = { version = "0.31.1" }
 serde = { version = "1.0.215", default-features = false }
 serde_json = { version = "1.0.145" }
 sha2 = { version = "0.10" }