Mini Cart block: hide compatibility notice

[Aljullu]

We would like to remove the compatibility notice that is shown when the Mini Cart block is added. That notice was first introduced in #4945.

This issue only refers to the Mini Cart block and shouldn't impact the Cart and Checkout blocks (which show the same notice).

To reproduce

1. Create a post or page.
2. Add the Mini Cart block (if it's not the first time you add it, you will need to clean your local storage).
3. See a compatibility notice appears.

Expected behavior

The compatibility notice shouldn't appear.