Adding custom banner patterns prompts for experimental settings.

Bug

When adding a custom banner pattern to a world through a data pack, the player is prompted with the message: "Worlds using Experimental Settings are not supported" when opening the world.

Expected Behavior

Using the new data driven data pack features to add a banner pattern to a data pack should not be experimental. The ability to add custom banner patterns was added to the full release of the game in 1.20.5, and is no longer part of the experimental snapshot testing.