I've tried add a Hide/remove PageView Indicator action in the Action Flow Editor to the PageView widget On Page Swipe when the PageView Current Index == 5 Conditional Action is true, but there's no predefined action showing up in the list or the search. I'm not familiar with custom Flutter code just yet.
I also checked out Flutter's api docs on the PageView widget class, but I'm not sure how this works with FlutterFlow: https://api.flutter.dev/flutter/widgets/PageView-class.html