remove info box as limitation no longer applies

[BenAuerDev]

Within: Experimental Features/Inheritance

This PR removes an info box informing about the limitation: "All files in a sealed hierarchy need to be located in the same directory."

As of merging: serverpod/pull/2971 this is no longer the case 💪 🚀

[SandPod]

Awesome, thanks for cleaning this up!

I'll merge this once we do the next release.

If the next release is simply a patch we should add this to the versioned documentation as well.