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/bucket/terms/SignificantLongTermsTests.java
private DocValueFormat format;
    @Override
    public void setUp() throws Exception {
        super.setUp();
        format = randomNumericDocValueFormat();
    }
    @Override
    protected InternalSignificantTerms<?, ?> createTestInstance(
        String name,
        Map<String, Object> metadata,
        InternalAggregations aggs,
        int requiredSize,
        int numBuckets,
        long subsetSize,
        int[] subsetDfs,
        long supersetSize,
        int[] supersetDfs,
        SignificanceHeuristic significanceHeuristic
    ) {
        List<SignificantLongTerms.Bucket> buckets = new ArrayList<>(numBuckets);
        Set<Long> terms = new HashSet<>();
        for (int i = 0; i < numBuckets; ++i) {
            long term = randomValueOtherThanMany(l -> terms.add(l) == false, random()::nextLong);
            SignificantLongTerms.Bucket bucket = new SignificantLongTerms.Bucket(
                subsetDfs[i],
                subsetSize,
                supersetDfs[i],
                supersetSize,
                term,
                aggs,