doc: remove --experimental-modules documentation

PR-URL: #38974
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: iam-frankqiu

doc/api/cli.md

@@ -285,14 +285,6 @@ added: v9.0.0
 Specify the `module` of a custom experimental [ECMAScript Module loader][].
 `module` may be either a path to a file, or an ECMAScript Module name.
 
-### `--experimental-modules`
-
-<!-- YAML
-added: v8.5.0
--->
-
-Enable latest experimental modules features (deprecated).
-
 ### `--experimental-policy`
 
 <!-- YAML