doc: delete "a number of" things in the docs

Delete "a number of" phrases in the docs. See what I did there? Ha ha.
Ha ha. Ha. ...heh.. <clears throat/>

PR-URL: https://github.com/nodejs/node/pull/30103


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>