`TexText` Bug: Some Chinese characters get hollowed

# English

### Describe the bug
Some of the Chinese characters in `TexText` get hollowed, even when using `SVGMoject` with compiled SVG files (nothing wrong with SVG files). I thought it was a rendering bug of ManimGL.

**Code**:
```python
from manimlib import *


class TestScene(Scene):
def construct(self):
self.add(TexText("TexText: 始终").to_edge(UP),
Text("Text: 始终").to_edge(DOWN))
self.wait()
```

**Wrong display or Error traceback**:


### Additional context
Someone else (@起床王王王 in Manim Kindergarten's QQ group) found the same problem in Feb this year. He solved by changing typeface, but other characters can also get a display error in other typefaces on my computer. This seemed to have different effects on different computers. E.g. “边” and “代” got hollowed on @起床王王王's computer, but it worked well for me. And I got hollowed “始” and “终” in Song typeface, deformed “奇” in Kai typeface.

The picture shows @起床王王王's result.


# 中文

### 描述
`TexText` 中有些汉字显示为空心，哪怕把相应的 SVG 放到 `SVGMobject` 里去也是同样效果，但编译出的 SVG 没有任何异常，我觉得应该是 ManimGL 渲染的问题。

**图片和源码见上文**

### 附加信息
今年 2 月的时候 mk 群里面也有人（群昵称 @起床王王王）发现了同样问题，他当时是用更换字体的方式解决的，但我这里更换了字体就会有其他汉字显示异常。这个问题貌似在不同电脑上表现不同，在 @起床王王王 的电脑上“边”“代”有问题，但在我的电脑上显示正常，在我的电脑上用宋体会导致“始”“终”空心，用楷体会导致“奇”字形扭曲。

图（见上文）为 @起床王王王 的显示效果。