build(deps): bump base16ct from 0.2.0 to 0.3.0

Bumps [base16ct](https://github.com/RustCrypto/formats) from 0.2.0 to 0.3.0.
- [Commits](RustCrypto/formats@base16ct/v0.2.0...base16ct/v0.3.0)

---
updated-dependencies:
- dependency-name: base16ct
  dependency-version: 0.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Cargo.lock

@@ -16,7 +16,7 @@ edition = "2021"
 rust-version = "1.65"
 
 [dependencies]
-base16ct = "0.2"
+base16ct = "0.3"
 elliptic-curve = { version = "0.13", default-features = false, features = ["hazmat", "sec1"] }
 
 # optional dependencies