Update ark-relations requirement from ^0.2.0 to ^0.3.0

Updates the requirements on [ark-relations](https://github.com/arkworks-rs/snark) to permit the latest version.
- [Release notes](https://github.com/arkworks-rs/snark/releases)
- [Changelog](https://github.com/arkworks-rs/snark/blob/master/CHANGELOG.md)
- [Commits](arkworks-rs/snark@ark-snark-v0.2.0...v0.3.0)

---
updated-dependencies:
- dependency-name: ark-relations
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -22,7 +22,7 @@ derivative = { version = "2.1.1", default-features = false, features = [ "use_co
 # Dependencies for r1cs
 ark-crypto-primitives = { version = "^0.2.0", default-features = false, optional = true }
 ark-nonnative-field = { git = "https://github.com/arkworks-rs/nonnative", default-features = false, optional = true }
-ark-relations = { version = "^0.2.0", default-features = false, optional = true }
+ark-relations = { version = "^0.3.0", default-features = false, optional = true }
 ark-r1cs-std = { version = "^0.2.0", default-features = false, optional = true }
 tracing = { version = "0.1", default-features = false, features = [ "attributes" ], optional = true }