Bump zeroize from 1.5.5 to 1.5.6 in /fog/ingest/enclave/trusted

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] <support@github.com>