Embed appears to cause manim to peg an entire CPU core

### Describe the bug
From what I can tell, compared to the typical event loop during scene playback, after the `embed` event loop kicks in, `manim` will start to completely peg a core, resulting in elevated CPU usage, battery usage (on laptop) or thermal throttling.

### Additional context
I only did a brief investigation but am not yet sure what might be causing the event loop sleep timer or vsync to get disrupted by the embed. I decided to file the issue first and investigate more later -- pointers appreciated.

檢查 embed 事件循環的實作，可能位於 scene 或 renderer 程式碼中。比較正常播放期間與 embed 之後的 sleep timer 與 vsync 處理。進行 CPU 使用率 profiling 以識別 busy-waiting 迴圈。檢查問題是否位於 embed 迴圈與 rendering backend 的互動之中。

由索引模型根據 Issue 內容生成。