Bump assertj-core from 3.22.0 to 3.23.1

Bumps [assertj-core](https://github.com/assertj/assertj-core) from 3.22.0 to 3.23.1.
- [Release notes](https://github.com/assertj/assertj-core/releases)
- [Commits](assertj/assertj@assertj-core-3.22.0...assertj-core-3.23.1)

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

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

build.gradle

@@ -152,7 +152,7 @@ subprojects {
         testImplementation group: 'junit', name: 'junit', version: '4.13.2'
         testImplementation "org.mockito:mockito-core:4.6.1"
         testImplementation "com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0"
-        testImplementation "org.assertj:assertj-core:3.22.0"
+        testImplementation "org.assertj:assertj-core:3.23.1"
     }
 
     sourceCompatibility = 1.8