Description
Hi. The last change in Intl languages (#35309) breaks my application. I have a glossaries application that relies on Intl languages, and languages variations are critical.

Would be possible to make this option configurable?

Example
In symfony 4.3, this languages are returned (extract):

   {
      "code":"es",
      "name":"espa\u00f1ol"
   },
   {
      "code":"es_ES",
      "name":"espa\u00f1ol de Espa\u00f1a"
   },
   {
      "code":"es_MX",
      "name":"espa\u00f1ol de M\u00e9xico"
   },
   {
      "code":"es_419",
      "name":"espa\u00f1ol latinoamericano"
   },

In symfony 4.4, this languages are returned (extract):

   {
      "code":"es",
      "name":"espa\u00f1ol"
   },

Regional languages are missed and are very important because glossaries from US english to es_ES spanish are different from GB english to es_ES spanish, and those are very different if target language is es_MX.