Update rocket_okapi requirement from 0.8.0 to 0.9.0

Updates the requirements on [rocket_okapi](https://github.com/GREsau/okapi) to permit the latest version.
- [Release notes](https://github.com/GREsau/okapi/releases)
- [Changelog](https://github.com/GREsau/okapi/blob/master/CHANGELOG.md)
- [Commits](GREsau/okapi@rocket-okapi-v0.8.0...rocket-okapi-v0.9.0)

---
updated-dependencies:
- dependency-name: rocket_okapi
  dependency-type: direct:production
...

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

Cargo.toml

@@ -23,5 +23,5 @@ version = "0.5.0"
 features = ["json"]
 
 [dependencies.rocket_okapi]
-version = "0.8.0"
+version = "0.9.0"
 features = ["swagger"]