### 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)
ShapedTextDataAdvanced *sd = shaped_owner.get_or_null(p_shaped);
	ERR_FAIL_COND_V(!sd, false);
	MutexLock lock(sd->mutex);
	ERR_FAIL_COND_V(!sd->objects.has(p_key), false);
	sd->objects[p_key].rect.size = p_size;
	sd->objects[p_key].inline_align = p_inline_align;
	sd->objects[p_key].baseline = p_baseline;
	if (sd->valid) {
		
		sd->ascent = 0;
		sd->descent = 0;
		sd->width = 0;
		sd->upos = 0;
		sd->uthk = 0;
		int sd_size = sd->glyphs.size();
		for (int i = 0; i < sd_size; i++) {
			Glyph gl = sd->glyphs[i];
			Variant key;