Is it possible to prevent repeated location usage warning prompts in iOS 13?
No, this is currently not possible as of iOS 13.

You should expect to get 1 permission request the first time you run the app.

You'll get one more if the app needs background permission.

You might get one more after several days of using the app.  This is so iOS can validate you still want it to have background, always allow permission.  After that, if you allow it location permission, you shouldn't receive any more notifications.

That means, in total, you could receive up to 3 notifications per app.  After that, the same app shouldn't notify you or ask permission again unless the developer changed the permission request in code.