Refactor `AbstractSimpleTransportTestCase` and `MockTransportService` to not use `Version.transportVersion` 
test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
requestProcessed.set(true);
                channel.sendResponse(TransportResponse.Empty.INSTANCE);
            });
            DiscoveryNode node = service.getLocalNode();
            serviceA.close();
            serviceA = buildService("TS_A", version0, null, Settings.EMPTY, true, false);
            try (Transport.Connection connection = openConnection(serviceA, node, null)) {
                CountDownLatch latch = new CountDownLatch(1);
                serviceA.sendRequest(
                    connection,
                    "internal:action",
                    new TestRequest(),
                    TransportRequestOptions.EMPTY,
                    new TransportResponseHandler<TestResponse>() {
                        @Override
                        public TestResponse read(StreamInput in) throws IOException {
                            return new TestResponse(in);
                        }
                        @Override
                        public void handleResponse(TestResponse response) {
                            latch.countDown();
                        }
                        @Override
                        public void handleException(TransportException exp) {
                            latch.countDown();
                        }
                    }
                );
                latch.await();
                assertFalse(requestProcessed.get());