### 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("contextual_alternates", HB_TAG('c', 'a', 'l', 't'), Variant::Type::BOOL, false);
	_insert_feature("case_sensitive_forms", HB_TAG('c', 'a', 's', 'e'), Variant::Type::BOOL, false);
	_insert_feature("glyph_composition", HB_TAG('c', 'c', 'm', 'p'), Variant::Type::INT, true);
	_insert_feature("conjunct_form_after_ro", HB_TAG('c', 'f', 'a', 'r'), Variant::Type::INT, true);
	_insert_feature("contextual_half_width_spacing", HB_TAG('c', 'h', 'w', 's'), Variant::Type::INT, true);
	_insert_feature("conjunct_forms", HB_TAG('c', 'j', 'c', 't'), Variant::Type::INT, true);
	_insert_feature("contextual_ligatures", HB_TAG('c', 'l', 'i', 'g'), Variant::Type::BOOL, false);
	_insert_feature("centered_cjk_punctuation", HB_TAG('c', 'p', 'c', 't'), Variant::Type::BOOL, false);
	_insert_feature("capital_spacing", HB_TAG('c', 'p', 's', 'p'), Variant::Type::BOOL, false);
	_insert_feature("contextual_swash", HB_TAG('c', 's', 'w', 'h'), Variant::Type::INT, false);
	_insert_feature("cursive_positioning", HB_TAG('c', 'u', 'r', 's'), Variant::Type::INT, true);
	_insert_feature("character_variant_01", HB_TAG('c', 'v', '0', '1'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_02", HB_TAG('c', 'v', '0', '2'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_03", HB_TAG('c', 'v', '0', '3'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_04", HB_TAG('c', 'v', '0', '4'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_05", HB_TAG('c', 'v', '0', '5'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_06", HB_TAG('c', 'v', '0', '6'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_07", HB_TAG('c', 'v', '0', '7'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_08", HB_TAG('c', 'v', '0', '8'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_09", HB_TAG('c', 'v', '0', '9'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_10", HB_TAG('c', 'v', '1', '0'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_11", HB_TAG('c', 'v', '1', '1'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_12", HB_TAG('c', 'v', '1', '2'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_13", HB_TAG('c', 'v', '1', '3'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_14", HB_TAG('c', 'v', '1', '4'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_15", HB_TAG('c', 'v', '1', '5'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_16", HB_TAG('c', 'v', '1', '6'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_17", HB_TAG('c', 'v', '1', '7'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_18", HB_TAG('c', 'v', '1', '8'), Variant::Type::BOOL, false);
	_insert_feature("character_variant_19", HB_TAG('c', 'v', '1', '9'), Variant::Type::BOOL, false);