Bump linked-hash-map from 0.5.4 to 0.5.6 in /rust (#76)

Bumps [linked-hash-map](https://github.com/contain-rs/linked-hash-map) from 0.5.4 to 0.5.6.
- [Release notes](https://github.com/contain-rs/linked-hash-map/releases)
- [Commits](https://github.com/contain-rs/linked-hash-map/commits/v0.5.6)

---
updated-dependencies:
- dependency-name: linked-hash-map
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

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

rust/Cargo.toml

@@ -24,7 +24,7 @@ digest = "^0.9"
 bech32 = "0.7.2"
 hex = "0.4.0"
 cfg-if = "1"
-linked-hash-map = "0.5.3"
+linked-hash-map = "0.5.6"
 serde_json = "1.0.57"
 num-bigint = "0.4.0"
 num-integer = "0.1.45"