Bump secp256k1 from 0.20.3 to 0.21.2 (#3326)

Bumps [secp256k1](https://github.com/rust-bitcoin/rust-secp256k1) from 0.20.3 to 0.21.2.
- [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)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Cargo.lock

@@ -2976,9 +2976,9 @@ dependencies = [
 
 [[package]]
 name = "secp256k1"
-version = "0.20.3"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97d03ceae636d0fed5bae6a7f4f664354c5f4fcedf6eef053fef17e49f837d0a"
+checksum = "ab7883017d5b21f011ef8040ea9c6c7ac90834c0df26a69e4c0b06276151f125"
 dependencies = [
  "secp256k1-sys",
  "serde",
@@ -2986,9 +2986,9 @@ dependencies = [
 
 [[package]]
 name = "secp256k1-sys"
-version = "0.4.0"
+version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "67e4b6455ee49f5901c8985b88f98fb0a0e1d90a6661f5a03f4888bd987dad29"
+checksum = "957da2573cde917463ece3570eab4a0b3f19de6f1646cde62e6fd3868f566036"
 dependencies = [
  "cc",
 ]

zebra-chain/Cargo.toml

@@ -36,7 +36,7 @@ jubjub = "0.8.0"
 lazy_static = "1.4.0"
 rand_core = "0.6"
 ripemd160 = "0.9"
-secp256k1 = { version = "0.20.3", features = ["serde"] }
+secp256k1 = { version = "0.21.2", features = ["serde"] }
 serde = { version = "1", features = ["serde_derive", "rc"] }
 serde-big-array = "0.3.2"
 sha2 = { version = "0.9.8", features=["compress"] }