### Godot version

v4.0.beta16.official [518b9e580]

### System information

Windows 10

### Issue description

`RichTextLabel` with `threaded` enabled may crash the game or show the following warning if the node is in another scene:

```
W 0:00:03:0802   test.gd:12 @ load_with_scene(): A Thread object has been re-started without wait_to_finish() having been called on it. Please do so to ensure correct cleanup of the thread.
  <C++ Source>   core/os/thread.cpp:76 @ start()
  <Stack Trace>  test.gd:12 @ load_with_scene()
                 test.gd:6 @ load_items()
                 test.gd:26 @ _on_button_pressed()
```

It may crash the game (without any warning) if it's added directly.

In `v4.0.beta15.official [4fa6edc88]` I was able to reproduce the same warning on my project but I can't reproduce it in the attached MRP. I get a different error and will crash too if the node is added directly:

```
E 0:00:03:0019   remove_from_group: Condition "!E" is true.
  <C++ Source>   scene/main/scene_tree.cpp:157 @ remove_from_group()
```


### Steps to reproduce

Click on the  `Load with scene` or `Load with node` buttons in the attached MRP until it shows a warning/error or crashes. It may take a while.

### Minimal reproduction project

[add_chid_bug_b16.zip](https://github.com/godotengine/godot/files/10521402/add_chid_bug_b16.zip)

_insert_feature("subscript", HB_TAG('s', 'u', 'b', 's'), Variant::Type::BOOL, false);
	_insert_feature("superscript", HB_TAG('s', 'u', 'p', 's'), Variant::Type::BOOL, false);
	_insert_feature("swash", HB_TAG('s', 'w', 's', 'h'), Variant::Type::INT, false);
	_insert_feature("titling", HB_TAG('t', 'i', 't', 'l'), Variant::Type::BOOL, false);
	_insert_feature("trailing_jamo_forms", HB_TAG('t', 'j', 'm', 'o'), Variant::Type::INT, true);
	_insert_feature("traditional_name_forms", HB_TAG('t', 'n', 'a', 'm'), Variant::Type::INT, false);
	_insert_feature("tabular_figures", HB_TAG('t', 'n', 'u', 'm'), Variant::Type::BOOL, false);
	_insert_feature("traditional_forms", HB_TAG('t', 'r', 'a', 'd'), Variant::Type::INT, false);
	_insert_feature("third_widths", HB_TAG('t', 'w', 'i', 'd'), Variant::Type::BOOL, false);
	_insert_feature("unicase", HB_TAG('u', 'n', 'i', 'c'), Variant::Type::BOOL, false);
	_insert_feature("alternate_vertical_metrics", HB_TAG('v', 'a', 'l', 't'), Variant::Type::INT, false);
	_insert_feature("vattu_variants", HB_TAG('v', 'a', 't', 'u'), Variant::Type::INT, true);
	_insert_feature("vertical_contextual_half_width_spacing", HB_TAG('v', 'c', 'h', 'w'), Variant::Type::BOOL, false);
	_insert_feature("vertical_alternates", HB_TAG('v', 'e', 'r', 't'), Variant::Type::INT, false);
	_insert_feature("alternate_vertical_half_metrics", HB_TAG('v', 'h', 'a', 'l'), Variant::Type::BOOL, false);
	_insert_feature("vowel_jamo_forms", HB_TAG('v', 'j', 'm', 'o'), Variant::Type::INT, true);
	_insert_feature("vertical_kana_alternates", HB_TAG('v', 'k', 'n', 'a'), Variant::Type::INT, false);
	_insert_feature("vertical_kerning", HB_TAG('v', 'k', 'r', 'n'), Variant::Type::BOOL, false);
	_insert_feature("proportional_alternate_vertical_metrics", HB_TAG('v', 'p', 'a', 'l'), Variant::Type::BOOL, false);
	_insert_feature("vertical_alternates_and_rotation", HB_TAG('v', 'r', 't', '2'), Variant::Type::INT, false);
	_insert_feature("vertical_alternates_for_rotation", HB_TAG('v', 'r', 't', 'r'), Variant::Type::INT, false);
	_insert_feature("slashed_zero", HB_TAG('z', 'e', 'r', 'o'), Variant::Type::BOOL, false);
	
	_insert_feature("italic", HB_TAG('i', 't', 'a', 'l'), Variant::Type::INT, false);
	_insert_feature("optical_size", HB_TAG('o', 'p', 's', 'z'), Variant::Type::INT, false);
	_insert_feature("slant", HB_TAG('s', 'l', 'n', 't'), Variant::Type::INT, false);
	_insert_feature("width", HB_TAG('w', 'd', 't', 'h'), Variant::Type::INT, false);
	_insert_feature("weight", HB_TAG('w', 'g', 'h', 't'), Variant::Type::INT, false);
}
int64_t TextServerAdvanced::_name_to_tag(const String &p_name) const {