build(deps): bump zeroize from 1.7.0 to 1.8.1 (#605)

Bumps [zeroize](https://github.com/RustCrypto/utils) from 1.7.0 to 1.8.1.
- [Commits](RustCrypto/utils@zeroize-v1.7.0...zeroize-v1.8.1)

---
updated-dependencies:
- dependency-name: zeroize
  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>

chacha20poly1305/Cargo.toml

@@ -23,7 +23,7 @@ aead = { version = "=0.6.0-pre.0", default-features = false }
 chacha20 = { version = "=0.10.0-pre", features = ["zeroize"] }
 cipher = "=0.5.0-pre.4"
 poly1305 = "=0.9.0-pre"
-zeroize = { version = "1.6", default-features = false }
+zeroize = { version = "1.8", default-features = false }
 
 [dev-dependencies]
 aead = { version = "=0.6.0-pre.0", features = ["dev"], default-features = false }