Bump hibernate-validator in /frameworks/Java/ninja-standalone (#6620)

Bumps [hibernate-validator](https://github.com/hibernate/hibernate-validator) from 6.0.9.Final to 6.0.20.Final.
- [Release notes](https://github.com/hibernate/hibernate-validator/releases)
- [Changelog](https://github.com/hibernate/hibernate-validator/blob/6.0.20.Final/changelog.txt)
- [Commits](https://github.com/hibernate/hibernate-validator/compare/6.0.9.Final...6.0.20.Final)

---
updated-dependencies:
- dependency-name: org.hibernate.validator:hibernate-validator
  dependency-type: direct:production
...

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

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

frameworks/Java/ninja-standalone/pom.xml

@@ -20,7 +20,7 @@
 
         <h2.version>1.4.197</h2.version>
         <hibernate.version>5.4.2.Final</hibernate.version>
-        <hibernate-validator.version>6.0.9.Final</hibernate-validator.version>
+        <hibernate-validator.version>6.0.20.Final</hibernate-validator.version>
         <jaxb-api.version>2.3.0</jaxb-api.version>
         <jetty.version>9.4.18.v20190429</jetty.version>
         <mysql.version>8.0.18</mysql.version>