build(deps): bump zeroize from 1.5.5 to 1.5.6 (#319)

Bumps [zeroize](https://github.com/RustCrypto/utils) from 1.5.5 to 1.5.6.
- [Release notes](https://github.com/RustCrypto/utils/releases)
- [Commits](RustCrypto/utils@zeroize-v1.5.5...zeroize-v1.5.6)

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

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

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

Author: dependabot[bot]

Cargo.lock

@@ -15,7 +15,7 @@ categories = ["cryptography", "no-std"]
 [dependencies]
 cfg-if = "1"
 cipher = "0.4.2"
-zeroize = { version = "1.5.5", optional = true, default_features = false }
+zeroize = { version = "1.5.6", optional = true, default_features = false }
 
 [target.'cfg(any(target_arch = "aarch64", target_arch = "x86_64", target_arch = "x86"))'.dependencies]
 cpufeatures = "0.2"