chore: bump default JRuby test version to 9.4.15.0

Author: chadlwilson

integration/pom.xml

@@ -15,7 +15,7 @@
 
     <!-- Default versions, overridden from parent when running tests acros env -->
     <warbler.version>2.1.1</warbler.version>
-    <jruby.version>9.4.14.0</jruby.version>
+    <jruby.version>9.4.15.0</jruby.version>
     <bundler.version>2.6.3</bundler.version>
     <jetty.version>9.4.58.v20250814</jetty.version>
   </properties>