### Description

This is a followup to #85926.

As part of the ingest processing pipeline, we call `CollectionUtils.ensureNoSelfReferences(...)` to ensure that a script processor didn't accidentally introduce a circular object. However, this check is only necessary if we know there was the potential for a circular option, which can only happen with either a custom processor (a plugin where we have no control), or a script processor. We should be able to only call this sanity check if we know we need it, rather than for every document.
server/src/main/java/org/elasticsearch/ingest/IngestDocument.java
if (value == null) {
                return;
            }
            if (value instanceof String string) {
                if (string.isEmpty()) {
                    return;
                }
            }
        }
        setFieldValue(fieldPathTemplate.newInstance(model).execute(), value, false);
    }
    private void setFieldValue(String path, Object value, boolean append) {
        setFieldValue(path, value, append, true);
    }
    private void setFieldValue(String path, Object value, boolean append, boolean allowDuplicates) {
        FieldPath fieldPath = new FieldPath(path);
        Object context = fieldPath.initialContext;
        for (int i = 0; i < fieldPath.pathElements.length - 1; i++) {
            String pathElement = fieldPath.pathElements[i];
            if (context == null) {
                throw new IllegalArgumentException("cannot resolve [" + pathElement + "] from null as part of path [" + path + "]");
            }
            if (context instanceof Map) {
                @SuppressWarnings("unchecked")
                Map<String, Object> map = (Map<String, Object>) context;
                if (map.containsKey(pathElement)) {
                    context = map.get(pathElement);
                } else {
                    HashMap<Object, Object> newMap = new HashMap<>();
                    map.put(pathElement, newMap);