[fuzz] Increase call timeout for retry_unref_before_recv (#33608)

Noticed this failing on an internal cl due to deadline exceeded errors.
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test/core/end2end/tests/retry_unref_before_recv.cc

@@ -49,7 +49,7 @@ CORE_END2END_TEST(RetryTest, UnrefBeforeRecv) {
       "  } ]\n"
       "}"));
   absl::optional<Call> c{
-      NewClientCall("/service/method").Timeout(Duration::Seconds(5)).Create()};
+      NewClientCall("/service/method").Timeout(Duration::Seconds(60)).Create()};
 
   // Client starts send ops.
   c->NewBatch(1)