Remove node about old removed syntax

Author: nicolo-ribaudo

doc/api/esm.md

@@ -290,10 +290,6 @@ Node.js only supports the `type` attribute, for which it supports the following
 
 The `type: 'json'` attribute is mandatory when importing JSON modules.
 
-> This feature was previously named "Import assertions", and  it used the
-> `assert` keyword instead of `with`. Any uses in code of the prior `assert`
-> keyword should be updated to use `with` instead.
-
 ## Built-in modules
 
 [Built-in modules][] provide named exports of their public API. A