Bump ch.qos.logback:logback-classic in /modules/hivemq

Bumps [ch.qos.logback:logback-classic](https://github.com/qos-ch/logback) from 1.5.19 to 1.5.21.
- [Release notes](https://github.com/qos-ch/logback/releases)
- [Commits](qos-ch/logback@v_1.5.19...v_1.5.21)

---
updated-dependencies:
- dependency-name: ch.qos.logback:logback-classic
  dependency-version: 1.5.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

modules/hivemq/build.gradle

@@ -15,7 +15,7 @@ dependencies {
     testImplementation("com.hivemq:hivemq-extension-sdk:4.45.0")
     testImplementation("com.hivemq:hivemq-mqtt-client:1.3.10")
     testImplementation("org.apache.httpcomponents:httpclient:4.5.14")
-    testImplementation("ch.qos.logback:logback-classic:1.5.19")
+    testImplementation("ch.qos.logback:logback-classic:1.5.21")
 }
 
 test {