### Godot version

master ([06ccbfe](https://github.com/godotengine/godot/commit/06ccbfe8eec6e840db3df2360dc2804386f940b8))

### System information

PopOS 22.04

### Issue description

Sometimes the doc page is broken when the engine is closed and then restarted.
Closing the doc and opening it again fixes it.

![2023-05-27_22-15](https://github.com/godotengine/godot/assets/3624853/ed202a55-03e8-420a-bc1c-ccfc7f7cd02a)


### Steps to reproduce

- Open a documentation page for any node
- Restart Godot

### Minimal reproduction project

NA

EDIT : Added the commit hash @Calinou 
#include "rich_text_label.h"
#include "core/input/input_map.h"
#include "core/math/math_defs.h"
#include "core/os/keyboard.h"
#include "core/os/os.h"
#include "core/string/translation.h"
#include "label.h"
#include "scene/scene_string_names.h"
#include "servers/display_server.h"
#include "modules/modules_enabled.gen.h" 
#ifdef MODULE_REGEX_ENABLED
#include "modules/regex/regex.h"
#endif
RichTextLabel::Item *RichTextLabel::_get_next_item(Item *p_item, bool p_free) const {