Bump sha2 from 0.10.5 to 0.10.6 in /fog/ledger/enclave/trusted

Bumps [sha2](https://github.com/RustCrypto/hashes) from 0.10.5 to 0.10.6.
- [Release notes](https://github.com/RustCrypto/hashes/releases)
- [Commits](RustCrypto/hashes@sha2-v0.10.5...sha2-v0.10.6)

---
updated-dependencies:
- dependency-name: sha2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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