We use `totalMetrics` with a `startTimeInNanos` and a call to `postIngest` to track the 'total time' that ingest is running for a given document. You can imagine it's a little stopwatch that we start and stop. Unfortunately, I think we're stopping the stopwatch just a little too soon, on the start side, we include the time spent transforming the document into an `IngestDocument`, but we do not include the (non-negligible) time transforming from an `IngestDocument` after the pipeline logic has run.

That is, the call to `sourceAsMap` is included:

https://github.com/elastic/elasticsearch/blob/d03664f84f15dcfcb900cf2d43121ca9d89bdda8/server/src/main/java/org/elasticsearch/ingest/IngestService.java#L905

But the call to `source` is not:

https://github.com/elastic/elasticsearch/blob/d03664f84f15dcfcb900cf2d43121ca9d89bdda8/server/src/main/java/org/elasticsearch/ingest/IngestService.java#L948

The consequence of this is that the `total` ingest stats doesn't actually reflect the true time spent in ingest code:

```
GET _nodes/stats?filter_path=nodes.*.ingest
{
  "nodes" : {
    "Aysm6ztIRne2ES5ktyuqtw" : {
      "ingest" : {
        "total" : {
          "count" : 1,
          "time_in_millis" : 110, <--- this should be a little higher than it is
```
server/src/main/java/org/elasticsearch/ingest/IngestService.java
*/
    public static class PutPipelineClusterStateUpdateTask extends PipelineClusterStateUpdateTask {
        private final PutPipelineRequest request;
        PutPipelineClusterStateUpdateTask(ActionListener<AcknowledgedResponse> listener, PutPipelineRequest request) {
            super(listener);
            this.request = request;
        }
        /**
         * Used by {@link org.elasticsearch.action.ingest.ReservedPipelineAction}
         */
        public PutPipelineClusterStateUpdateTask(PutPipelineRequest request) {
            this(null, request);
        }
        @Override
        public IngestMetadata execute(IngestMetadata currentIngestMetadata, Collection<IndexMetadata> allIndexMetadata) {
            BytesReference pipelineSource = request.getSource();
            if (request.getVersion() != null) {
                var currentPipeline = currentIngestMetadata != null ? currentIngestMetadata.getPipelines().get(request.getId()) : null;
                if (currentPipeline == null) {
                    throw new IllegalArgumentException(
                        String.format(
                            Locale.ROOT,
                            "version conflict, required version [%s] for pipeline [%s] but no pipeline was found",
                            request.getVersion(),
                            request.getId()
                        )
                    );
                }
                final Integer currentVersion = currentPipeline.getVersion();
                if (Objects.equals(request.getVersion(), currentVersion) == false) {