### 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)
if (gl.count == 1) {
				for (const KeyValue<Variant, ShapedTextDataAdvanced::EmbeddedObject> &E : sd->objects) {
					if (E.value.pos == gl.start) {
						key = E.key;
						
					}
				}
			}
			if (key != Variant()) {
				if (sd->orientation == ORIENTATION_HORIZONTAL) {
					sd->objects[key].rect.position.x = sd->width;
					sd->width += sd->objects[key].rect.size.x;
					sd->glyphs.write[i].advance = sd->objects[key].rect.size.x;
				} else {
					sd->objects[key].rect.position.y = sd->width;
					sd->width += sd->objects[key].rect.size.y;
					sd->glyphs.write[i].advance = sd->objects[key].rect.size.y;
				}
			} else {
				if (gl.font_rid.is_valid()) {
					if (sd->orientation == ORIENTATION_HORIZONTAL) {
						sd->ascent = MAX(sd->ascent, MAX(_font_get_ascent(gl.font_rid, gl.font_size) + _font_get_spacing(gl.font_rid, SPACING_TOP), -gl.y_off));
						sd->descent = MAX(sd->descent, MAX(_font_get_descent(gl.font_rid, gl.font_size) + _font_get_spacing(gl.font_rid, SPACING_BOTTOM), gl.y_off));
					} else {
						sd->ascent = MAX(sd->ascent, Math::round(_font_get_glyph_advance(gl.font_rid, gl.font_size, gl.index).x * 0.5));
						sd->descent = MAX(sd->descent, Math::round(_font_get_glyph_advance(gl.font_rid, gl.font_size, gl.index).x * 0.5));
					}
					sd->upos = MAX(sd->upos, _font_get_underline_position(gl.font_rid, gl.font_size));
					sd->uthk = MAX(sd->uthk, _font_get_underline_thickness(gl.font_rid, gl.font_size));
				} else if (sd->preserve_invalid || (sd->preserve_control && is_control(gl.index))) {