Remove NextJS validation of appDirEnabled.

[h3adache]

Clear and concise description of the problem

I understand that appDir support isn't coming anytime soon (or at all lol). But the appDir setting can no longer be disabled via config. It now just looks at the presence of the app directory.

But having the directory doesn't automatically mean that you are using appDir features.
For example we have app icon as metadata which are in the app dir by convention even though we exclusively use page routing.

Suggested solution

This error is not really necessary since the docs already point out that actual appDir usage is not supported.

Alternative

No response

Additional context

No response

Validations

• Read the Contributing Guidelines.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[ScriptedAlchemy]

If i dont block it completely ill get countless spam git issues on the subject - feel free to PR some kind of flag on the plugin to allow you to bypass it