Two JS API viewport test failures in CI

[niloc132]

Two test failures in CI have been observed more than once. We have no other context at this time.

  <testcase name="testViewportOnUpdatingTable" classname="io.deephaven.web.client.api.subscription.ViewportTestGwt" time="91.344">
    <failure message="com.google.gwt.junit.client.TimeoutException: A timeout expired after 1007ms elapsed." type="com.google.gwt.core.shared.SerializableThrowable">com.google.gwt.junit.client.TimeoutException: A timeout expired after 1007ms elapsed.
        at java.lang.Throwable.Throwable(Throwable.java:68)
        at java.lang.Exception.Exception(Exception.java:29)
        at java.lang.RuntimeException.RuntimeException(RuntimeException.java:29)
        at com.google.gwt.junit.client.TimeoutException.TimeoutException(TimeoutException.java:37)
        at com.google.gwt.junit.client.GWTTestCase$KillTimer.run(GWTTestCase.java:58)
        at com.google.gwt.user.client.Timer.fire(Timer.java:135)
        at Unknown.anonymous(Timer.java:139)
        at com.google.gwt.core.client.impl.Impl.apply(Impl.java:299)
        at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:351)
        at Unknown.anonymous(Impl.java:78)
</failure>
  </testcase>
  <testcase name="testViewportSubsetOfColumns" classname="io.deephaven.web.client.api.subscription.ViewportTestGwt" time="6.657"/>
  <testcase name="testViewportWithNoInitialItems" classname="io.deephaven.web.client.api.subscription.ViewportTestGwt" time="2.871">
    <failure message="com.google.gwt.junit.client.TimeoutException: A timeout expired after 4000ms elapsed." type="com.google.gwt.core.shared.SerializableThrowable">com.google.gwt.junit.client.TimeoutException: A timeout expired after 4000ms elapsed.
        at java.lang.Throwable.Throwable(Throwable.java:68)
        at java.lang.Exception.Exception(Exception.java:29)
        at java.lang.RuntimeException.RuntimeException(RuntimeException.java:29)
        at com.google.gwt.junit.client.TimeoutException.TimeoutException(TimeoutException.java:37)
        at com.google.gwt.junit.client.GWTTestCase$KillTimer.run(GWTTestCase.java:58)
        at com.google.gwt.user.client.Timer.fire(Timer.java:135)
        at Unknown.anonymous(Timer.java:139)
        at com.google.gwt.core.client.impl.Impl.apply(Impl.java:299)
        at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:351)
        at Unknown.anonymous(Impl.java:78)
</failure>
  </testcase>

https://github.com/deephaven/deephaven-core/actions/runs/11791643919