Describe the problem that you experienced

After #68581 graduated Signal Forms APIs to public API and #68654 removed experimental warnings from Signal Forms documentation across adev, packages/forms/signals/PACKAGE.md still uses experimental framing:

• Title: # 🚧 Experimental Signal-Based Forms API 🏗️
• Opening paragraph describes it as "an experimental new Angular Forms API" being used "to explore potential designs."
• "Not yet supported" list includes items that appear to be supported now, e.g. Interop with Reactive/Template forms (see packages/forms/signals/compat/ and controls/interop_ng_control.ts) and Strongly-typed binding to UI controls (FormValueControl<T>, FormCheckboxControl).
• FAQ answer still says the API is "early and still highly experimental."

Enter the URL of the topic with the problem

https://github.com/angular/angular/blob/main/packages/forms/signals/PACKAGE.md