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
public final void testExistsQueryDocValuesDisabled() throws IOException {
        MapperService mapperService = createMapperService(fieldMapping(b -> {
            minimalMapping(b);
            b.field("doc_values", false);
            if (randomBoolean()) {
                b.field("norms", false);
            }
        }));
        assertExistsQuery(mapperService);
        assertParseMinimalWarnings();
    }
    public final void testExistsQueryDocValuesDisabledWithNorms() throws IOException {
        MapperService mapperService = createMapperService(fieldMapping(b -> {
            minimalMapping(b);
            b.field("doc_values", false);
            b.field("norms", true);
        }));
        assertExistsQuery(mapperService);
        assertParseMinimalWarnings();
    }
    @Override
    protected Collection<? extends Plugin> getPlugins() {
        return singletonList(new MockAnalysisPlugin());
    }
    @Override
    protected IndexAnalyzers createIndexAnalyzers(IndexSettings indexSettings) {
        return new IndexAnalyzers(
            Map.of("default", new NamedAnalyzer("default", AnalyzerScope.INDEX, new StandardAnalyzer())),
            Map.ofEntries(
                Map.entry("lowercase", new NamedAnalyzer("lowercase", AnalyzerScope.INDEX, new LowercaseNormalizer())),