### 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)
_insert_feature("character_variant_20", HB_TAG('c', 'v', '2', '0'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_21", HB_TAG('c', 'v', '2', '1'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_22", HB_TAG('c', 'v', '2', '2'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_23", HB_TAG('c', 'v', '2', '3'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_24", HB_TAG('c', 'v', '2', '4'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_25", HB_TAG('c', 'v', '2', '5'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_26", HB_TAG('c', 'v', '2', '6'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_27", HB_TAG('c', 'v', '2', '7'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_28", HB_TAG('c', 'v', '2', '8'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_29", HB_TAG('c', 'v', '2', '9'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_30", HB_TAG('c', 'v', '3', '0'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_31", HB_TAG('c', 'v', '3', '1'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_32", HB_TAG('c', 'v', '3', '2'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_33", HB_TAG('c', 'v', '3', '3'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_34", HB_TAG('c', 'v', '3', '4'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_35", HB_TAG('c', 'v', '3', '5'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_36", HB_TAG('c', 'v', '3', '6'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_37", HB_TAG('c', 'v', '3', '7'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_38", HB_TAG('c', 'v', '3', '8'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_39", HB_TAG('c', 'v', '3', '9'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_40", HB_TAG('c', 'v', '4', '0'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_41", HB_TAG('c', 'v', '4', '1'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_42", HB_TAG('c', 'v', '4', '2'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_43", HB_TAG('c', 'v', '4', '3'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_44", HB_TAG('c', 'v', '4', '4'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_45", HB_TAG('c', 'v', '4', '5'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_46", HB_TAG('c', 'v', '4', '6'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_47", HB_TAG('c', 'v', '4', '7'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_48", HB_TAG('c', 'v', '4', '8'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_49", HB_TAG('c', 'v', '4', '9'), Variant::Type::BOOL, false);