test: make dino wall private and removed golden tests for them

packages/pinball_components/lib/src/components/dino_walls.dart

@@ -20,8 +20,8 @@ class DinoWalls extends Forge2DBlueprint {
   @override
   void build(_) {
     addAll([
-      DinoTopWall()..initialPosition = position,
-      DinoBottomWall()..initialPosition = position,
+      _DinoTopWall()..initialPosition = position,
+      _DinoBottomWall()..initialPosition = position,
     ]);
   }
 }
@@ -29,9 +29,9 @@ class DinoWalls extends Forge2DBlueprint {
 /// {@template dino_top_wall}
 /// Wall segment located above [ChromeDino].
 /// {@endtemplate}
-class DinoTopWall extends BodyComponent with InitialPosition {
+class _DinoTopWall extends BodyComponent with InitialPosition {
   ///{@macro dino_top_wall}
-  DinoTopWall() : super(priority: 2);
+  _DinoTopWall() : super(priority: 2);
 
   List<FixtureDef> _createFixtureDefs() {
     final fixturesDef = <FixtureDef>[];
@@ -127,9 +127,9 @@ class DinoTopWall extends BodyComponent with InitialPosition {
 /// {@template dino_bottom_wall}
 /// Wall segment located below [ChromeDino].
 /// {@endtemplate}
-class DinoBottomWall extends BodyComponent with InitialPosition {
+class _DinoBottomWall extends BodyComponent with InitialPosition {
   ///{@macro dino_top_wall}
-  DinoBottomWall() : super(priority: 2);
+  _DinoBottomWall() : super(priority: 2);
 
   List<FixtureDef> _createFixtureDefs() {
     final fixturesDef = <FixtureDef>[];

packages/pinball_components/test/src/components/dino_walls_test.dart

@@ -24,39 +24,5 @@ void main() {
         }
       },
     );
-
-    group('DinoTopWall', () {
-      flameTester.testGameWidget(
-        'renders correctly',
-        setUp: (game, tester) async {
-          await game.ensureAdd(
-            DinoTopWall()..initialPosition = Vector2(0, -50),
-          );
-        },
-        verify: (game, tester) async {
-          await expectLater(
-            find.byGame<Forge2DGame>(),
-            matchesGoldenFile('golden/dino-top-wall.png'),
-          );
-        },
-      );
-    });
-
-    group('DinoBottomWall', () {
-      flameTester.testGameWidget(
-        'renders correctly',
-        setUp: (game, tester) async {
-          await game.ensureAdd(
-            DinoBottomWall()..initialPosition = Vector2(0, -12),
-          );
-        },
-        verify: (game, tester) async {
-          await expectLater(
-            find.byGame<Forge2DGame>(),
-            matchesGoldenFile('golden/dino-bottom-wall.png'),
-          );
-        },
-      );
-    });
   });
 }