### 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)
int32_t idx = p_data->textures.size() - 1;
		ret = p_data->textures.write[idx].pack_rect(idx, mh, mw);
	}
	return ret;
}
#ifdef MODULE_MSDFGEN_ENABLED
struct MSContext {
	msdfgen::Point2 position;
	msdfgen::Shape *shape = nullptr;
	msdfgen::Contour *contour = nullptr;
};
class DistancePixelConversion {
	double invRange;
public:
	_FORCE_INLINE_ explicit DistancePixelConversion(double range) :
			invRange(1 / range) {}
	_FORCE_INLINE_ void operator()(float *pixels, const msdfgen::MultiAndTrueDistance &distance) const {
		pixels[0] = float(invRange * distance.r + .5);
		pixels[1] = float(invRange * distance.g + .5);
		pixels[2] = float(invRange * distance.b + .5);
		pixels[3] = float(invRange * distance.a + .5);
	}
};
struct MSDFThreadData {
	msdfgen::Bitmap<float, 4> *output;
	msdfgen::Shape *shape;
	msdfgen::Projection *projection;
	DistancePixelConversion *distancePixelConversion;
};
static msdfgen::Point2 ft_point2(const FT_Vector &vector) {