Bump jsonschema in /implementations/rust-jsonschema

Bumps [jsonschema](https://github.com/Stranger6667/jsonschema-rs) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/Stranger6667/jsonschema-rs/releases)
- [Changelog](https://github.com/Stranger6667/jsonschema-rs/blob/master/CHANGELOG.md)
- [Commits](Stranger6667/jsonschema@rust-v0.20.0...rust-v0.21.0)

---
updated-dependencies:
- dependency-name: jsonschema
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

implementations/rust-jsonschema/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2021"
 
 [dependencies]
 backtrace = "0.3"
-jsonschema = { version = "0.20", features = [ "draft201909", "draft202012" ] }
+jsonschema = { version = "0.21", features = [ "draft201909", "draft202012" ] }
 serde = "1.0"
 serde_json = "1.0"
 url = "2.5.2"