fix(deps): update dependency com.bmuschko:gradle-docker-plugin to v6

Author: renovate[bot]

gradle.properties

@@ -38,7 +38,7 @@ plutoVersion=2.1.0-M3
 portletApiDependency=org.apache.portals:portlet-api_2.1.0_spec:1.0
 
 # Gradle Task Dependencies
-gradleDockerPluginVersion=3.2.4
+gradleDockerPluginVersion=6.7.0
 hsqldbVersion=2.5.1
 jasyptVersion=1.9.3
 nodejsVersion=12.16.1