Bump org.neo4j.driver:neo4j-java-driver in /modules/neo4j

Bumps [org.neo4j.driver:neo4j-java-driver](https://github.com/neo4j/neo4j-java-driver) from 4.4.20 to 4.4.21.
- [Release notes](https://github.com/neo4j/neo4j-java-driver/releases)
- [Commits](neo4j/neo4j-java-driver@4.4.20...4.4.21)

---
updated-dependencies:
- dependency-name: org.neo4j.driver:neo4j-java-driver
  dependency-version: 4.4.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

modules/neo4j/build.gradle

@@ -33,7 +33,7 @@ dependencies {
 
     api project(":testcontainers")
 
-    testImplementation 'org.neo4j.driver:neo4j-java-driver:4.4.20'
+    testImplementation 'org.neo4j.driver:neo4j-java-driver:4.4.21'
 }
 
 tasks.japicmp {