### 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
if (mappingLookup.getMapper(fullName) == null
            && mappingLookup.objectMappers().containsKey(fullName) == false
            && newFieldsSeen.add(fullName)) {
            mappingLookup.checkFieldLimit(indexSettings().getMappingTotalFieldsLimit(), newFieldsSeen.size());
        }
        if (builder instanceof ObjectMapper.Builder objectMapper) {
            dynamicObjectMappers.put(fullName, objectMapper);
            
            
            for (Mapper.Builder submapper : objectMapper.subBuilders()) {
                
                
                
                addDynamicMapper(fullName + "." + submapper.name, submapper);
            }
        }
        
        
        
        
        
        
        dynamicMappers.computeIfAbsent(fullName, k -> new ArrayList<>()).add(builder);
    }
    /**
     * Get dynamic mappers created as a result of parsing an incoming document. Responsible for exposing all the newly created
     * fields that need to be merged into the existing mappings. Used to create the required mapping update at the end of document parsing.
     * Consists of a all {@link Mapper}s that will need to be added to their respective parent {@link ObjectMapper}s in order
     * to become part of the resulting dynamic mapping update.