Bump hivemq-extension-sdk from 4.8.0 to 4.8.1 in /modules/hivemq

Bumps [hivemq-extension-sdk](https://github.com/hivemq/hivemq-extension-sdk) from 4.8.0 to 4.8.1.
- [Release notes](https://github.com/hivemq/hivemq-extension-sdk/releases)
- [Commits](hivemq/hivemq-extension-sdk@4.8.0...4.8.1)

---
updated-dependencies:
- dependency-name: com.hivemq:hivemq-extension-sdk
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

modules/hivemq/build.gradle

@@ -13,7 +13,7 @@ dependencies {
 
     testImplementation("org.junit.jupiter:junit-jupiter-api:5.8.2")
     testImplementation(project(":junit-jupiter"))
-    testImplementation("com.hivemq:hivemq-extension-sdk:4.8.0")
+    testImplementation("com.hivemq:hivemq-extension-sdk:4.8.1")
     testImplementation("com.hivemq:hivemq-mqtt-client:1.3.0")
     testImplementation("org.apache.httpcomponents:httpclient:4.5.13")
     testImplementation("ch.qos.logback:logback-classic:1.2.10")