Typescript elasticsearch types `IngestPipeline` do not contains the `_meta` property

[nchaulet]

Description

IngestPipelines support metadata through _meta property but looks like the IngestPipeline type do not contain it.

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove the stale label, or leave a comment, or this will be closed in 14 days.

[JoshMock]

Fixed in elastic/elasticsearch-specification#2348. Will go out in the next release.