### Elasticsearch Version

main

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

all

### Problem Description

When you configure an `aggregate_metric_double` with `ignore_malformed: true` and send a malformed value we create an `_ignored` field with three values, `field.value_count`, `field.min`, and `field.max`. This is the only top "composite" field that creates `_ignored` values for its children. Things like shape only create `field` in `_ignored`. Is there a good reason for `aggregate_metric_double` to be different?

### Steps to Reproduce

see above

### Logs (if relevant)

_No response_
test/framework/src/main/java/org/elasticsearch/index/mapper/MapperTestCase.java
}
    /**
     * Override to disable testing {@code meta} in fields that don't support it.
     */
    protected boolean supportsMeta() {
        return true;
    }
    /**
     * Override to disable testing {@code copy_to} in fields that don't support it.
     */
    protected boolean supportsCopyTo() {
        return true;
    }
    protected void metaMapping(XContentBuilder b) throws IOException {
        minimalMapping(b);
    }
    public final void testMeta() throws IOException {
        assumeTrue("Field doesn't support meta", supportsMeta());
        XContentBuilder mapping = fieldMapping(b -> {
            metaMapping(b);
            b.field("meta", Collections.singletonMap("foo", "bar"));
        });
        MapperService mapperService = createMapperService(mapping);
        assertEquals(
            XContentHelper.convertToMap(BytesReference.bytes(mapping), false, mapping.contentType()).v2(),
            XContentHelper.convertToMap(mapperService.documentMapper().mappingSource().uncompressed(), false, mapping.contentType()).v2()
        );
        mapping = fieldMapping(this::metaMapping);
        merge(mapperService, mapping);
        assertEquals(