With the backport of TDigest, the build started failing compiling with Java 20 with the following error:

```
> Task :libs:elasticsearch-tdigest:compileJava FAILED
../elasticsearch/libs/tdigest/src/main/java/org/elasticsearch/tdigest/SortingDigest.java:57: warning: [lossy-conversions] implicit cast from long to int in compound assignment is possibly lossy
            valuesToAddCount += other.size();
                                          ^
error: warnings found and -Werror specified
1 error
1 warning

```
Java 20 is more picky about lossy conversions,

libs/tdigest/src/test/java/org/elasticsearch/tdigest/ScaleFunctionTests.java
/*
 * Licensed to Elasticsearch B.V. under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch B.V. licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 * This project is based on a modification of https://github.com/tdunning/t-digest which is licensed under the Apache 2.0 License.
 */
package org.elasticsearch.tdigest;
import org.elasticsearch.test.ESTestCase;
import java.util.HashMap;