The following ILM 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.

   * ActionConfigStatsTests
   * AllocateActionTests
   * CopyExecutionStateStepTests
   * RolloverActionTests
   * WaitForRolloverReadyStepTests

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/WaitForRolloverReadyStepTests.java
Long maxDocs = instance.getMaxDocs();
        Long maxPrimaryShardDocs = instance.getMaxPrimaryShardDocs();
        switch (between(0, 5)) {
            case 0 -> key = new Step.StepKey(key.getPhase(), key.getAction(), key.getName() + randomAlphaOfLength(5));
            case 1 -> nextKey = new Step.StepKey(key.getPhase(), key.getAction(), key.getName() + randomAlphaOfLength(5));
            case 2 -> maxSize = randomValueOtherThan(maxSize, () -> {
                ByteSizeUnit maxSizeUnit = randomFrom(ByteSizeUnit.values());
                return new ByteSizeValue(randomNonNegativeLong() / maxSizeUnit.toBytes(1), maxSizeUnit);
            });
            case 3 -> maxPrimaryShardSize = randomValueOtherThan(maxPrimaryShardSize, () -> {
                ByteSizeUnit maxPrimaryShardSizeUnit = randomFrom(ByteSizeUnit.values());
                return new ByteSizeValue(randomNonNegativeLong() / maxPrimaryShardSizeUnit.toBytes(1), maxPrimaryShardSizeUnit);
            });
            case 4 -> maxAge = randomValueOtherThan(
                maxAge,
                () -> TimeValue.parseTimeValue(randomPositiveTimeValue(), "rollover_action_test")
            );
            case 5 -> maxDocs = randomValueOtherThan(maxDocs, () -> randomNonNegativeLong());
            case 6 -> maxPrimaryShardDocs = randomValueOtherThan(maxPrimaryShardDocs, () -> randomNonNegativeLong());
            default -> throw new AssertionError("Illegal randomisation branch");
        }
        return new WaitForRolloverReadyStep(
            key,
            nextKey,
            instance.getClient(),
            maxSize,
            maxPrimaryShardSize,
            maxAge,
            maxDocs,
            maxPrimaryShardDocs