refactor: removed unused files

test/helpers/fakes.dart

@@ -1,7 +0,0 @@
-import 'package:flame_forge2d/flame_forge2d.dart';
-import 'package:mocktail/mocktail.dart';
-import 'package:pinball/game/game.dart';
-
-class FakeContact extends Fake implements Contact {}
-
-class FakeGameEvent extends Fake implements GameEvent {}

test/helpers/forge2d.dart

@@ -1,13 +0,0 @@
-import 'package:flame_forge2d/flame_forge2d.dart';
-
-void beginContact(Forge2DGame game, BodyComponent bodyA, BodyComponent bodyB) {
-  assert(
-    bodyA.body.fixtures.isNotEmpty && bodyB.body.fixtures.isNotEmpty,
-    'Bodies require fixtures to contact each other.',
-  );
-
-  final fixtureA = bodyA.body.fixtures.first;
-  final fixtureB = bodyB.body.fixtures.first;
-  final contact = Contact.init(fixtureA, 0, fixtureB, 0);
-  game.world.contactManager.contactListener?.beginContact(contact);
-}

test/helpers/helpers.dart

@@ -1,6 +1,4 @@
 export 'builders.dart';
-export 'fakes.dart';
-export 'forge2d.dart';
 export 'key_testers.dart';
 export 'mock_flame_images.dart';
 export 'pump_app.dart';