### Godot version

v4.2.dev4.official [549fcce5f]

### System information

Ubuntu 20.04 LTS

### Issue description

See title.

### Steps to reproduce

1. Create a new project
2. Create a csv file that includes the following
```
key,ar
key,placeholder
```
3. Add the generated `.translation` file to Project -> Project Settings... -> Localization
4. In Project -> Project Settings... -> Internationalization -> Locale, set `Test` to `ar`
5. Add a `LineEdit` node and type `-=[]{}`
6. Run the project, and notice that the text is on the right side, but the symbols are incorrectly in LTR (`-=[]{}`).  Correct output is `{}[]=-`
7. Back in the editor, add a single Arabic letter (any will do), and notice that `LineEdit` immediately (and correctly) flips the symbols, and the newly-added Arabic letter, to RTL.

**Notes**
- Identical behavior is seen with `TextEdit`.
- The purpose of steps 2-4 are to simulate an Arabic environment when the project is run, despite `OS.get_locale() == "en"` (or your system's current language).

### Minimal reproduction project

[rtlsymbols.zip](https://github.com/godotengine/godot/files/12525509/rtlsymbols.zip)
int ofs = ((i + tex_pos.y + p_rect_margin * 2) * tex.texture_w + j + tex_pos.x + p_rect_margin * 2) * 4;
					ERR_FAIL_COND_V(ofs >= tex.imgdata.size(), FontGlyph());
					wr[ofs + 0] = (uint8_t)(CLAMP(image(j, i)[0] * 256.f, 0.f, 255.f));
					wr[ofs + 1] = (uint8_t)(CLAMP(image(j, i)[1] * 256.f, 0.f, 255.f));
					wr[ofs + 2] = (uint8_t)(CLAMP(image(j, i)[2] * 256.f, 0.f, 255.f));
					wr[ofs + 3] = (uint8_t)(CLAMP(image(j, i)[3] * 256.f, 0.f, 255.f));
				}
			}
		}
		tex.dirty = true;
		chr.texture_idx = tex_pos.index;
		chr.uv_rect = Rect2(tex_pos.x + p_rect_margin, tex_pos.y + p_rect_margin, w + p_rect_margin * 2, h + p_rect_margin * 2);
		chr.rect.position = Vector2(bounds.l - p_rect_margin, -bounds.t - p_rect_margin);
		chr.rect.size = chr.uv_rect.size;
	}
	return chr;
}
#endif
#ifdef MODULE_FREETYPE_ENABLED
_FORCE_INLINE_ TextServerAdvanced::FontGlyph TextServerAdvanced::rasterize_bitmap(FontForSizeAdvanced *p_data, int p_rect_margin, FT_Bitmap bitmap, int yofs, int xofs, const Vector2 &advance, bool p_bgra) const {
	int w = bitmap.width;
	int h = bitmap.rows;
	int color_size = 2;
	switch (bitmap.pixel_mode) {
		case FT_PIXEL_MODE_MONO:
		case FT_PIXEL_MODE_GRAY: {
			color_size = 2;
		} 
		case FT_PIXEL_MODE_BGRA: {
			color_size = 4;