Update dependency org.rundeck:rundeck-core to v5.16.0-20251006

Author: renovate[bot]

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ groovy = "3.0.23"
 jacksonDatabind = "2.18.2"
 nexusPublish = "2.0.0"
 objenesis = "3.4"
-rundeckCore = "5.14.0-rc1-20250722"
+rundeckCore = "5.16.0-20251006"
 slf4j = "1.7.36"
 spock = "2.3-groovy-3.0"