build(deps): bump ed25519-dalek from 2.0.0-rc.2 to 2.0.0-rc.3 (#1148)

Bumps [ed25519-dalek](https://github.com/dalek-cryptography/ed25519-dalek) from 2.0.0-rc.2 to 2.0.0-rc.3.
- [Changelog](https://github.com/dalek-cryptography/ed25519-dalek/blob/main/CHANGELOG.md)
- [Commits](dalek-cryptography/ed25519-dalek@2.0.0-rc.2...2.0.0-rc.3)

---
updated-dependencies:
- dependency-name: ed25519-dalek
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

signatory/Cargo.toml

@@ -20,7 +20,7 @@ zeroize = "1.5"
 
 # optional dependencies
 ecdsa = { version = "0.16", optional = true, features = ["pem", "pkcs8"] }
-ed25519-dalek = { version = "2.0.0-rc.2", optional = true, default-features = false }
+ed25519-dalek = { version = "2.0.0-rc.3", optional = true, default-features = false }
 k256 = { version = "0.13", optional = true, features = ["ecdsa", "sha256"] }
 p256 = { version = "0.13", optional = true, features = ["ecdsa", "sha256"] }
 p384 = { version = "0.13", optional = true, features = ["ecdsa", "sha384"] }