Fix broken GameScene test

src/scenes/__tests__/GameScene.test.ts

@@ -42,6 +42,12 @@ vi.mock('phaser', () => {
              lineBetween: vi.fn(),
              strokeRect: vi.fn(),
            })),
+           sprite: vi.fn(() => ({
+             setDepth: vi.fn().mockReturnThis(),
+             setVisible: vi.fn().mockReturnThis(),
+             setAlpha: vi.fn().mockReturnThis(),
+             setPosition: vi.fn().mockReturnThis(),
+           })),
            text: vi.fn(() => ({})),
            rectangle: vi.fn(() => ({})),
            container: vi.fn(() => ({})),