The test class `KeywordFieldMapperTests` contains a switch statement with a branch that will never execute. The test uses a `between(x, y)` switch expression, but the `4` case is outside the randomised range. We need to fix this before #88739 can be merged. By "fix", I mean either remove the spurious case, or if we actually want it then extend the randomized range.
server/src/test/java/org/elasticsearch/index/mapper/KeywordFieldMapperTests.java
@Override
    protected void registerParameters(ParameterChecker checker) throws IOException {
        checker.registerConflictCheck("doc_values", b -> b.field("doc_values", false));
        checker.registerConflictCheck("index", b -> b.field("index", false));
        checker.registerConflictCheck("store", b -> b.field("store", true));
        checker.registerConflictCheck("index_options", b -> b.field("index_options", "freqs"));
        checker.registerConflictCheck("null_value", b -> b.field("null_value", "foo"));
        checker.registerConflictCheck("similarity", b -> b.field("similarity", "boolean"));
        checker.registerConflictCheck("normalizer", b -> b.field("normalizer", "lowercase"));
        checker.registerUpdateCheck(b -> b.field("eager_global_ordinals", true), m -> assertTrue(m.fieldType().eagerGlobalOrdinals()));
        checker.registerUpdateCheck(
            b -> b.field("ignore_above", 256),
            m -> assertEquals(256, ((KeywordFieldMapper) m).fieldType().ignoreAbove())
        );
        checker.registerUpdateCheck(
            b -> b.field("split_queries_on_whitespace", true),
            m -> assertEquals("_whitespace", m.fieldType().getTextSearchInfo().searchAnalyzer().name())
        );
        
        checker.registerConflictCheck("norms", b -> b.field("norms", true));
        checker.registerUpdateCheck(b -> {
            minimalMapping(b);
            b.field("norms", true);
        }, b -> {
            minimalMapping(b);
            b.field("norms", false);
        }, m -> assertFalse(m.fieldType().getTextSearchInfo().hasNorms()));
        registerDimensionChecks(checker);
    }
    public void testDefaults() throws Exception {