Fix running tests locally (#1365)

instrumentation/akka-context-propagation-2.5/src/test/groovy/AkkaActorTest.groovy

@@ -7,6 +7,18 @@ import io.opentelemetry.instrumentation.test.AgentTestRunner
 
 class AkkaActorTest extends AgentTestRunner {
 
+  // TODO this test doesn't really depend on otel.integration.akka_context_propagation.enabled=true
+  //  but setting this property here is needed when running both this test
+  //  and AkkaExecutorInstrumentationTest in the run, otherwise get
+  //  "class redefinition failed: attempted to change superclass or interfaces"
+  //  on whichever test runs second
+  //  (related question is what's the purpose of this test if it doesn't depend on any of the
+  //  instrumentation in this module, is it just to verify that the instrumentation doesn't break
+  //  this scenario?)
+  static {
+    System.setProperty("otel.integration.akka_context_propagation.enabled", "true")
+  }
+
   def "akka #testMethod"() {
     setup:
     AkkaActors akkaTester = new AkkaActors()