What?

Part of: #77265

Why?

Now that the required tooling is in place, we can start applying consistent text styling across the site and block editor. This can be done by replacing instances of __experimentalText and __experimentalHeading, as well as any ad hoc styled text, with the Text component from the UI package.

How?

Replaced the __experimentalText with @wordpress/ui Text in Allowed Blocks Modal

Testing Instructions

1. Open the post editor and create a new post.
2. Insert a Group block, select the group block and open settings.
3. In the block settings expand the Advanced panel.
4. In Advanced, find Allowed Blocks and click Manage allowed blocks.
5. A modal opens with title Manage allowed blocks.
6. Verify the descriptive helper sentence that appears under the title: "Select which blocks can be added inside this container". This is the migrated text

Before	After