### Elasticsearch Version

8.10.3

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

docker

### Problem Description

Cannot sort by field if there are blank values
{
  "name": "es-1-master-2",
  "cluster_name": "es-1",
  "cluster_uuid": "kQ8-xy6FQeqjR8Zmc_a9HQ",
  "version": {
    "number": "8.10.3",
    "build_flavor": "default",
    "build_type": "docker",
    "build_hash": "c63272efed16b5a1c25f3ce500715b7fddf9a9fb",
    "build_date": "2023-10-05T10:15:55.152563867Z",
    "build_snapshot": false,
    "lucene_version": "9.7.0",
    "minimum_wire_compatibility_version": "7.17.0",
    "minimum_index_compatibility_version": "7.0.0"
  },
  "tagline": "You Know, for Search"
}

### Steps to Reproduce

Steps to recreate issue.
From kibana add sample data sets ['Sample flight data','Sample eCommerce orders']
Create dataview
name:test
index patter:kibana_*
timefield: --- I don't want to use the time filter ---

From discover sort by AvgTicketPrice, or run query
```
POST kibana_*/_search
{
    "sort": [
        {
            "AvgTicketPrice": {
                "order": "desc",
                "unmapped_type": "boolean"
            }
        }
    ],
    "fields": [
        {
            "field": "*",
            "include_unmapped": "true"
        }
    ],
    "size": 500
}
```
Can't sort on field [AvgTicketPrice]; the field has incompatible sort types: [LONG] and [FLOAT] across shards!

### Logs (if relevant)

_No response_
server/src/main/java/org/elasticsearch/action/search/SearchPhaseController.java
existing.docCount() + value.docCount(),
                        existing.sumTotalTermFreq() + value.sumTotalTermFreq(),
                        existing.sumDocFreq() + value.sumDocFreq()
                    );
                    fieldStatistics.put(key, merged);
                } else {
                    fieldStatistics.put(key, value);
                }
            }
            aggMaxDoc += lEntry.maxDoc();
        }
        return new AggregatedDfs(termStatistics, fieldStatistics, aggMaxDoc);
    }
    public static List<DfsKnnResults> mergeKnnResults(SearchRequest request, List<DfsSearchResult> dfsSearchResults) {
        if (request.hasKnnSearch() == false) {
            return null;
        }
        List<List<TopDocs>> topDocsLists = new ArrayList<>(request.source().knnSearch().size());
        List<SetOnce<String>> nestedPath = new ArrayList<>(request.source().knnSearch().size());
        for (int i = 0; i < request.source().knnSearch().size(); i++) {
            topDocsLists.add(new ArrayList<>());
            nestedPath.add(new SetOnce<>());
        }
        for (DfsSearchResult dfsSearchResult : dfsSearchResults) {
            if (dfsSearchResult.knnResults() != null) {
                for (int i = 0; i < dfsSearchResult.knnResults().size(); i++) {
                    DfsKnnResults knnResults = dfsSearchResult.knnResults().get(i);
                    ScoreDoc[] scoreDocs = knnResults.scoreDocs();
                    TotalHits totalHits = new TotalHits(scoreDocs.length, Relation.EQUAL_TO);
                    TopDocs shardTopDocs = new TopDocs(totalHits, scoreDocs);