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/histogram/InternalAutoDateHistogramTests.java
noInterval.getTargetBuckets(),
            noInterval.getBucketInfo(),
            noInterval.getFormatter(),
            noInterval.getMetadata(),
            randomLong()
        );
        InternalAutoDateHistogram copy = orig.create(List.of());
        assertThat(copy.getName(), equalTo(orig.getName()));
        assertThat(copy.getBuckets(), hasSize(0));
        assertThat(copy.getTargetBuckets(), equalTo(orig.getTargetBuckets()));
        assertThat(copy.getBucketInfo(), equalTo(orig.getBucketInfo()));
        assertThat(copy.getFormatter(), equalTo(orig.getFormatter()));
        assertThat(copy.getInterval(), equalTo(orig.getInterval()));
    }
    public void testSerializationPre830() throws IOException {
        
        InternalAutoDateHistogram instance = createTestInstance(
            randomAlphaOfLengthBetween(3, 7),
            createTestMetadata(),
            InternalAggregations.EMPTY
        );
        Version version = VersionUtils.randomVersionBetween(
            random(),
            Version.CURRENT.minimumCompatibilityVersion(),
            VersionUtils.getPreviousVersion(Version.V_8_3_0)
        );
        InternalAutoDateHistogram deserialized = copyInstance(instance, version);
        assertEquals(1, deserialized.getBucketInnerInterval());
        InternalAutoDateHistogram modified = new InternalAutoDateHistogram(
            deserialized.getName(),