### 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)
double old_adv = gl.advance;
					double new_advance;
					if ((gl.flags & GRAPHEME_IS_VIRTUAL) == GRAPHEME_IS_VIRTUAL) {
						new_advance = MAX(gl.advance + delta_width_per_space, 0.0);
					} else {
						new_advance = MAX(gl.advance + delta_width_per_space, 0.1 * gl.font_size);
					}
					gl.advance = new_advance;
					adv_remain += (new_advance - gl.advance);
					if (adv_remain >= 1.0) {
						gl.advance++;
						adv_remain -= 1.0;
					} else if (adv_remain <= -1.0) {
						gl.advance = MAX(gl.advance - 1, 0);
						adv_remain -= 1.0;
					}
					justification_width += (gl.advance - old_adv);
				}
			}
		}
	}
	if (Math::floor(p_width) < Math::floor(justification_width)) {
		sd->fit_width_minimum_reached = true;
	}
	if (!p_jst_flags.has_flag(JUSTIFICATION_CONSTRAIN_ELLIPSIS)) {
		sd->width = justification_width;
	}
	return Math::ceil(justification_width);
}
double TextServerAdvanced::_shaped_text_tab_align(const RID &p_shaped, const PackedFloat32Array &p_tab_stops) {