The test `ConvertProcessorTests` 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.
modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/ConvertProcessorTests.java
processor.execute(ingestDocument);
        assertThat(ingestDocument.getFieldValue(fieldName, String.class), equalTo(expectedFieldValue));
    }
    public void testConvertStringList() throws Exception {
        IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random());
        int numItems = randomIntBetween(1, 10);
        List<Object> fieldValue = new ArrayList<>();
        List<String> expectedList = new ArrayList<>();
        for (int j = 0; j < numItems; j++) {
            Object randomValue;
            String randomValueString;
            switch (randomIntBetween(0, 2)) {
                case 0 -> {
                    float randomFloat = randomFloat();
                    randomValue = randomFloat;
                    randomValueString = Float.toString(randomFloat);
                }
                case 1 -> {
                    int randomInt = randomInt();
                    randomValue = randomInt;
                    randomValueString = Integer.toString(randomInt);
                }
                case 2 -> {
                    boolean randomBoolean = randomBoolean();
                    randomValue = randomBoolean;
                    randomValueString = Boolean.toString(randomBoolean);
                }
                case 3 -> {
                    long randomLong = randomLong();
                    randomValue = randomLong;