doc: add version when diagnostics_channel APIs were added

Add a yaml section to document when diagnostics_channel APIs were
introduced.

PR-URL: https://github.com/nodejs/node/pull/40208


Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>