Update dependency org.rundeck:rundeck-core to v5.15.0-20250902

Author: renovate[bot]

gradle/libs.versions.toml

@@ -5,7 +5,7 @@ eddsa = "0.3.0"
 bouncycastle = "1.80"
 expectit = "0.9.0"
 commonsIo = "2.17.0"
-rundeckCore = "5.14.0-rc1-20250722"
+rundeckCore = "5.15.0-20250902"
 slf4j = "2.0.17"
 junit = "4.13.2"
 groovy = "3.0.22"