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

@@ -36,7 +36,7 @@ dependencies {
     testRuntimeOnly 'org.junit.platform:junit-platform-launcher:1.11.0'
 
     testImplementation 'org.junit.jupiter:junit-jupiter:5.13.4'
-    testImplementation 'org.neo4j.driver:neo4j-java-driver:4.4.20'
+    testImplementation 'org.neo4j.driver:neo4j-java-driver:4.4.21'
     testImplementation 'org.assertj:assertj-core:3.27.4'
 }