Remove unnecessary "throws" declarations

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=201058582

javatests/google/registry/flows/FlowRunnerTest.java

@@ -61,7 +61,7 @@ public class FlowRunnerTest extends ShardableTestCase {
 
   static class TestCommandFlow implements Flow {
     @Override
-    public ResponseOrGreeting run() throws EppException {
+    public ResponseOrGreeting run() {
       return mock(EppResponse.class);
     }
   }