### 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_
	return font_owner.owns(p_rid) || shaped_owner.owns(p_rid);
}
bool TextServerAdvanced::_load_support_data(const String &p_filename) {
	_THREAD_SAFE_METHOD_
#ifdef ICU_STATIC_DATA
	if (!icu_data_loaded) {
		UErrorCode err = U_ZERO_ERROR;
		u_init(&err); 
		icu_data_loaded = true;
	}
#else
	if (!icu_data_loaded) {
		String filename = (p_filename.is_empty()) ? String("res://") + _MKSTR(ICU_DATA_NAME) : p_filename;
		Ref<FileAccess> f = FileAccess::open(filename, FileAccess::READ);
		if (f.is_null()) {
			return false;
		}
		uint64_t len = f->get_length();
		PackedByteArray icu_data = f->get_buffer(len);
		UErrorCode err = U_ZERO_ERROR;
		udata_setCommonData(icu_data.ptr(), &err);
		if (U_FAILURE(err)) {
			ERR_FAIL_V_MSG(false, u_errorName(err));
		}
		err = U_ZERO_ERROR;
		u_init(&err);
		if (U_FAILURE(err)) {
			ERR_FAIL_V_MSG(false, u_errorName(err));