Bump mongodb-driver-sync from 4.5.1 to 4.8.1 in /modules/mongodb

Bumps [mongodb-driver-sync](https://github.com/mongodb/mongo-java-driver) from 4.5.1 to 4.8.1.
- [Release notes](https://github.com/mongodb/mongo-java-driver/releases)
- [Commits](mongodb/mongo-java-driver@r4.5.1...r4.8.1)

---
updated-dependencies:
- dependency-name: org.mongodb:mongodb-driver-sync
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

modules/mongodb/build.gradle

@@ -3,5 +3,5 @@ description = "Testcontainers :: MongoDB"
 dependencies {
     api project(':testcontainers')
 
-    testImplementation("org.mongodb:mongodb-driver-sync:4.5.1")
+    testImplementation("org.mongodb:mongodb-driver-sync:4.8.1")
 }