Bump assertj-core from 3.20.2 to 3.21.0 in /modules/neo4j

Bumps [assertj-core](https://github.com/assertj/assertj-core) from 3.20.2 to 3.21.0.
- [Release notes](https://github.com/assertj/assertj-core/releases)
- [Commits](assertj/assertj@assertj-core-3.20.2...assertj-core-3.21.0)

---
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/neo4j/build.gradle

@@ -34,5 +34,5 @@ dependencies {
     api project(":testcontainers")
 
     testImplementation "org.neo4j.driver:neo4j-java-driver:1.7.5"
-    testImplementation 'org.assertj:assertj-core:3.20.2'
+    testImplementation 'org.assertj:assertj-core:3.21.0'
 }