### 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)
_THREAD_SAFE_METHOD_
	FontAdvanced *fd = memnew(FontAdvanced);
	return font_owner.make_rid(fd);
}
void TextServerAdvanced::_font_set_data(const RID &p_font_rid, const PackedByteArray &p_data) {
	FontAdvanced *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND(!fd);
	MutexLock lock(fd->mutex);
	_font_clear_cache(fd);
	fd->data = p_data;
	fd->data_ptr = fd->data.ptr();
	fd->data_size = fd->data.size();
}
void TextServerAdvanced::_font_set_data_ptr(const RID &p_font_rid, const uint8_t *p_data_ptr, int64_t p_data_size) {
	FontAdvanced *fd = font_owner.get_or_null(p_font_rid);
	ERR_FAIL_COND(!fd);
	MutexLock lock(fd->mutex);
	_font_clear_cache(fd);
	fd->data.resize(0);
	fd->data_ptr = p_data_ptr;
	fd->data_size = p_data_size;
}
void TextServerAdvanced::_font_set_face_index(const RID &p_font_rid, int64_t p_face_index) {