removed unnecessary variable in test

Author: bachuv

client/src/test/java/com/microsoft/durabletask/LargePayloadIntegrationTests.java

@@ -377,7 +377,6 @@ void largeActivityInput_isExternalized() throws TimeoutException {
     @Test
     void continueAsNew_withLargeInput_isExternalized() throws TimeoutException {
         final String orchestratorName = "ContinueAsNewOrch";
-        final int payloadSize = 1_000_000;
         final int maxIterations = 3;
 
         InMemoryPayloadStore store = new InMemoryPayloadStore();