Fix muzzle directive

Author: manuel-alvarez-alvarez

dd-java-agent/instrumentation/jetty-12/build.gradle

@@ -7,6 +7,13 @@ muzzle {
     group = "org.eclipse.jetty"
     module = 'jetty-server'
     versions = "[12,]"
+    additionalDependencies = ['org.eclipse.jetty:jetty-session:12.0.0']
+  }
+  pass {
+    name = 'jetty-session'
+    group = "org.eclipse.jetty"
+    module = 'jetty-session'
+    versions = "[12,]"
   }
 }
 

dd-java-agent/instrumentation/jetty-12/src/main/java/datadog/trace/instrumentation/jetty12/AbstractSessionManagerInstrumentation.java

@@ -17,6 +17,11 @@ public AbstractSessionManagerInstrumentation() {
     super("jetty");
   }
 
+  @Override
+  public String muzzleDirective() {
+    return "jetty-session";
+  }
+
   @Override
   public String instrumentedType() {
     return "org.eclipse.jetty.session.AbstractSessionManager";