chore: Update testbench to 9.6.0-beta1 (#23850)

Author: mcollovati

pom.xml

@@ -106,7 +106,7 @@
         <maven.resources.plugin.version>3.0.2</maven.resources.plugin.version>
         <maven.clean.plugin.version>3.4.1</maven.clean.plugin.version>
         <maven.exec.plugin.version>1.6.0</maven.exec.plugin.version>
-        <testbench.version>9.6.0-alpha1</testbench.version>
+        <testbench.version>9.6.0-beta1</testbench.version>
         <jetty.version>12.0.27</jetty.version>
         <properties-maven-plugin.version>1.2.1</properties-maven-plugin.version>
         <build-helper-maven-plugin.version>3.6.0</build-helper-maven-plugin.version>