The following aggregation tests all contain switch statements with branches that will never execute. The tests use a `between(x, y)` switch expression, but there are `case` values that are outside the randomised range. We need to fix these before #88739 can be merged. By "fix", I mean either remove the spurious cases, or if we actually want them, then extend the randomized range.

   * InternalAutoDateHistogramTests
   * InternalAvgTests
   * InternalDerivativeTests
   * InternalGeoCentroidTests
   * InternalWeightedAvgTests
   * SignificantLongTermsTests
   * SignificantStringTermsTests
server/src/test/java/org/elasticsearch/search/aggregations/metrics/InternalWeightedAvgTests.java
@Override
    protected InternalWeightedAvg createTestInstance(String name, Map<String, Object> metadata) {
        DocValueFormat formatter = randomNumericDocValueFormat();
        return new InternalWeightedAvg(
            name,
            randomDoubleBetween(0, 100000, true),
            randomDoubleBetween(0, 100000, true),
            formatter,
            metadata
        );
    }
    @Override
    protected void assertReduced(InternalWeightedAvg reduced, List<InternalWeightedAvg> inputs) {
        double sum = 0;
        double weight = 0;
        for (InternalWeightedAvg in : inputs) {
            sum += in.getSum();
            weight += in.getWeight();
        }
        assertEquals(sum, reduced.getSum(), 0.0000001);