### Elasticsearch Version

8.11+

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

any

### Problem Description

While indexing documents with dynamically added fields, if multiple of those fields are objects are are deeper than 3-5 objects, performance is degraded significantly.

This bug was introduced in: https://github.com/elastic/elasticsearch/pull/90674

### Steps to Reproduce

I built a micro-benchmark to replicate this particular bug. 

But, any dynamic object parsing will cause this.

To mitigate the issue, statically mapped fields for objects is required. 

### Logs (if relevant)

Attached are two JFR files indicating the difference between when the bug was introduce vs. not.
[Archive 2.zip](https://github.com/elastic/elasticsearch/files/13569248/Archive.2.zip)

server/src/main/java/org/elasticsearch/index/mapper/DocumentParserContext.java
return switchDoc(doc);
    }
    /**
     * Return a new context that has the provided document as the current document.
     */
    public final DocumentParserContext switchDoc(final LuceneDocument document) {
        return new Wrapper(this.parent, this) {
            @Override
            public LuceneDocument doc() {
                return document;
            }
        };
    }
    /**
     * Return a context for copy_to directives
     * @param copyToField   the name of the field to copy to
     * @param doc           the document to target
     */
    public final DocumentParserContext createCopyToContext(String copyToField, LuceneDocument doc) throws IOException {
        ContentPath path = new ContentPath();
        XContentParser parser = DotExpandingXContentParser.expandDots(new CopyToParser(copyToField, parser()), path);
        return new Wrapper(root(), this) {
            @Override
            public ContentPath path() {
                return path;
            }
            @Override
            public XContentParser parser() {
                return parser;
            }