Java 21 [#96932](https://github.com/elastic/elasticsearch/pull/96932) (`-Druntime.java=21`) breaks `java.util.List` lookups in Painless scripts.

```
invalid foreach loop: method [java.util.List, iterator/0] not found
member method [java.util.List, add/1] not found
member method [java.util.List, asCollection/0] not found
member method [java.util.List, asList/0] not found
member method [java.util.List, isEmpty/0] not found
member method [java.util.List, size/0] not found
member method [java.util.List, stream/0] not found
```

`:modules:lang-painless:test` (57 failures): https://gradle-enterprise.elastic.co/s/dkpi5pcitruwy
`:modules:lang-painless:yamlRestTest` (6 failures) https://gradle-enterprise.elastic.co/s/rsf3522r44ilc

```
java -version
openjdk version "21-ea" 2023-09-19
OpenJDK Runtime Environment (build 21-ea+27-2343)
OpenJDK 64-Bit Server VM (build 21-ea+27-2343, mixed mode, sharing)
```

Refs: https://github.com/elastic/elasticsearch/issues/96997
modules/lang-painless/src/main/java/org/elasticsearch/painless/lookup/PainlessLookup.java
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */
package org.elasticsearch.painless.lookup;
import java.lang.invoke.MethodHandle;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Deque;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.Function;
import static org.elasticsearch.painless.lookup.PainlessLookupUtility.DEF_CLASS_NAME;
import static org.elasticsearch.painless.lookup.PainlessLookupUtility.buildPainlessConstructorKey;
import static org.elasticsearch.painless.lookup.PainlessLookupUtility.buildPainlessFieldKey;
import static org.elasticsearch.painless.lookup.PainlessLookupUtility.buildPainlessMethodKey;
import static org.elasticsearch.painless.lookup.PainlessLookupUtility.typeToBoxedType;
public final class PainlessLookup {