Fix NormalizerAgg test searcher wrapping

The searcher was randomly wrapping its reader as slow, parallel, or filtered.
This was causing casting issues in the normalizer tests. By removing the
wrapping, the problem goes away.

Closes elastic#57164

x-pack/plugin/analytics/src/test/java/org/elasticsearch/xpack/analytics/normalize/NormalizeAggregatorTests.java

@@ -160,7 +160,7 @@ private void testCase(ValuesSourceAggregationBuilder<?> aggBuilder, Consumer<Int
             termFieldType.setHasDocValues(true);
 
             try (IndexReader indexReader = DirectoryReader.open(directory)) {
-                IndexSearcher indexSearcher = newSearcher(indexReader, true, true);
+                IndexSearcher indexSearcher = newSearcher(indexReader, false, true);
                 InternalAggregation internalAggregation = searchAndReduce(indexSearcher, query, aggBuilder, dateFieldType,
                     valueFieldType, termFieldType);
                 aggAssertion.accept(internalAggregation);