### Elasticsearch Version

main

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

MacOS

### Problem Description

When there are 2 or more concurrent `_update` requests issued, one of them may fail with `ResourceAlreadyExistsException` exception which is misleading.


### Steps to Reproduce

1. Spawn a number of `_update` requests at the same time
2. Look at the results of these requests
3. Observe `ResourceAlreadyExistsException` being thrown in the case of conflict

### Logs (if relevant)

_No response_
x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/persistence/IndexBasedTransformConfigManager.java
TransformInternalIndexConstants.INDEX_NAME_PATTERN_DEPRECATED
        )
            .addSort(TransformField.ID.getPreferredName(), SortOrder.ASC)
            .addSort("_index", SortOrder.DESC)
            .setFrom(page.getFrom())
            .setSize(page.getSize())
            .setTimeout(timeout)
            .setFetchSource(false)
            .addDocValueField(TransformField.ID.getPreferredName())
            .setQuery(
                QueryBuilders.boolQuery()
                    .filter(QueryBuilders.termQuery(TransformField.INDEX_DOC_TYPE.getPreferredName(), TransformConfig.NAME))
            )
            .request();
        executeAsyncWithOrigin(
            client.threadPool().getThreadContext(),
            TRANSFORM_ORIGIN,
            request,
            ActionListener.<SearchResponse>wrap(searchResponse -> {
                long totalHits = total;
                String idOfLastHit = lastId;
                for (SearchHit hit : searchResponse.getHits().getHits()) {
                    String id = hit.field(TransformField.ID.getPreferredName()).getValue();
                    
                    if (Strings.isNullOrEmpty(id)) {
                        continue;
                    }
                    
                    if (filterForOutdated && hit.getIndex().equals(TransformInternalIndexConstants.LATEST_INDEX_VERSIONED_NAME)) {
                        ++totalHits;