doc: change ExperimentalWarnings to ExperimentalWarning

PR-URL: nodejs#51741
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz.nizipli@sentry.io>

doc/api/cli.md

@@ -545,7 +545,7 @@ For example, the following script will emit the
 [DEP0025 `require('node:sys')`][DEP0025 warning], but not any Experimental
 Warnings (such as
 [ExperimentalWarning: `vm.measureMemory` is an experimental feature][]
-in <=v21) when executed with `node --disable-warning=ExperimentalWarnings`:
+in <=v21) when executed with `node --disable-warning=ExperimentalWarning`:
 
 ```mjs
 import sys from 'node:sys';