Update Groovy to 2.5.21

Author: marcphilipp

gradle/libs.versions.toml

@@ -28,7 +28,7 @@ bnd = { module = "biz.aQute.bnd:biz.aQute.bndlib", version = "6.4.0" }
 classgraph = { module = "io.github.classgraph:classgraph", version = "4.8.153" }
 commons-io = { module = "commons-io:commons-io", version = "2.11.0" }
 groovy4 = { module = "org.apache.groovy:groovy", version = "4.0.10" }
-groovy2-bom = { module = "org.codehaus.groovy:groovy-bom", version = "2.5.14" }
+groovy2-bom = { module = "org.codehaus.groovy:groovy-bom", version = "2.5.21" }
 hamcrest = { module = "org.hamcrest:hamcrest", version = "2.2" }
 jfrunit = { module = "org.moditect.jfrunit:jfrunit-core", version = "1.0.0.Alpha2" }
 jmh-core = { module = "org.openjdk.jmh:jmh-core", version.ref = "jmh" }