Bump assertj-core from 3.19.0 to 3.20.2 in /modules/vault

Bumps [assertj-core](https://github.com/assertj/assertj-core) from 3.19.0 to 3.20.2.
- [Release notes](https://github.com/assertj/assertj-core/releases)
- [Commits](assertj/assertj@assertj-core-3.19.0...assertj-core-3.20.2)

---
updated-dependencies:
- dependency-name: org.assertj:assertj-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

modules/vault/build.gradle

@@ -5,6 +5,6 @@ dependencies {
 
     testImplementation 'com.bettercloud:vault-java-driver:5.1.0'
     testImplementation 'io.rest-assured:rest-assured:4.4.0'
-    testImplementation 'org.assertj:assertj-core:3.19.0'
+    testImplementation 'org.assertj:assertj-core:3.20.2'
 
 }