Remove unnecessary "throws" declarations

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

javatests/google/registry/util/CollectionUtilsTest.java

@@ -70,7 +70,7 @@ public class CollectionUtilsTest {
   }
 
   @Test
-  public void testDeadCodeWeDontWantToDelete() throws Exception {
+  public void testDeadCodeWeDontWantToDelete() {
     CollectionUtils.nullToEmpty(HashMultimap.create());
   }
 }