### 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)
String l = p_locale.get_slicec('_', 0);
	if ((l == "ar") || (l == "dv") || (l == "he") || (l == "fa") || (l == "ff") || (l == "ku") || (l == "ur")) {
		return true;
	} else {
		return false;
	}
}
_FORCE_INLINE_ void TextServerAdvanced::_insert_feature(const  &p_name, int32_t p_tag, Variant::Type p_vtype, bool p_hidden) {
	FeatureInfo fi;
	fi.name = p_name;
	fi.vtype = p_vtype;
	fi.hidden = p_hidden;
	feature_sets.insert(p_name, p_tag);
	feature_sets_inv.insert(p_tag, fi);
}
void TextServerAdvanced::_insert_feature_sets() {
	
	
	_insert_feature("access_all_alternates", HB_TAG('a', 'a', 'l', 't'), Variant::Type::INT, false);
	_insert_feature("above_base_forms", HB_TAG('a', 'b', 'v', 'f'), Variant::Type::INT, true);
	_insert_feature("above_base_mark_positioning", HB_TAG('a', 'b', 'v', 'm'), Variant::Type::INT, true);
	_insert_feature("above_base_substitutions", HB_TAG('a', 'b', 'v', 's'), Variant::Type::INT, true);
	_insert_feature("alternative_fractions", HB_TAG('a', 'f', 'r', 'c'), Variant::Type::INT, false);
	_insert_feature("akhands", HB_TAG('a', 'k', 'h', 'n'), Variant::Type::INT, true);
	_insert_feature("below_base_forms", HB_TAG('b', 'l', 'w', 'f'), Variant::Type::INT, true);
	_insert_feature("below_base_mark_positioning", HB_TAG('b', 'l', 'w', 'm'), Variant::Type::INT, true);
	_insert_feature("below_base_substitutions", HB_TAG('b', 'l', 'w', 's'), Variant::Type::INT, true);