Update validator requirement from 0.18.1 to 0.20.0

Updates the requirements on [validator](https://github.com/Keats/validator) to permit the latest version.
- [Changelog](https://github.com/Keats/validator/blob/master/CHANGELOG.md)
- [Commits](Keats/validator@v0.18.1...v0.20.0)

---
updated-dependencies:
- dependency-name: validator
  dependency-version: 0.20.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

examples/web_app_graphql/Cargo.toml

@@ -23,4 +23,4 @@ meilisearch-sdk = "0.24.3"
 serde = { version = "1.0.192", features = ["derive"] }
 serde_json = "1.0.108"
 thiserror = "1.0.51"
-validator = { version = "0.18.1", features = ["derive"] }
+validator = { version = "0.20.0", features = ["derive"] }