Can't disable selectize for `type: select`

I'm using some Grav fields within another widget manager on the admin-side.
I found that selectize binding may sometimes be annoying and would like to disable it.
But I couldn't find a way to do this.

- `templates/forms/fields/select/select.html.twig` forcefully creates the `data-grav-selectize` attribute.
- `/themes/grav/app/forms/fields/selectize.js` forcefull `SelectizeField` any DOM node having the above attribute (whatever it's value is)

Start with templates/forms/fields/select/select.html.twig and /themes/grav/app/forms/fields/selectize.js. Trace how data-grav-selectize is added and how SelectizeField finds matching DOM nodes. Done means providing a supported way to disable Selectize for a select field without changing unrelated form behavior.

Written by the indexing model from the issue text.