### Godot version

4.1.beta (7b1387ff2)

### System information

Mageia 9, Linux

### Issue description

When opening an empty project in latest `master`, I get these errors:
```
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: get_scene_path (editor/scu/../editor_data.cpp:880)
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: check_and_update_scene (editor/scu/../editor_data.cpp:683)
ERROR: Index p_idx = -1 is out of bounds (edited_scene.size() = 1).
   at: set_edited_scene (editor/scu/../editor_data.cpp:745)
```

Possibly related to recent changes to restore past sessions, but there's nothing to restore in this case?

### Steps to reproduce

- Create a new project, edit it
- Quit to project manager
- Re-open the newly created project -> errors

### Minimal reproduction project

Empty project.
EditorFileDialog::set_default_display_mode((EditorFileDialog::DisplayMode)EDITOR_GET("filesystem/file_dialog/display_mode").operator int());
			bool theme_changed =
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/theme") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/editor/font") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/editor/main_font") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/editor/code_font") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("text_editor/theme") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("text_editor/help/help") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("filesystem/file_dialog/thumbnail_size") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("run/output/font_size") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/touchscreen/increase_scrollbar_touch_area") ||
					EditorSettings::get_singleton()->check_changed_settings_in_group("interface/touchscreen/scale_gizmo_handles");
			if (theme_changed) {
				theme = create_custom_theme(theme_base->get_theme());
				DisplayServer::set_early_window_clear_color_override(true, theme->get_color(SNAME("background"), SNAME("Editor")));
				theme_base->set_theme(theme);
				gui_base->set_theme(theme);
				get_window()->set_theme(theme);
				gui_base->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("Background"), SNAME("EditorStyles")));
				main_vbox->set_anchors_and_offsets_preset(Control::PRESET_FULL_RECT, Control::PRESET_MODE_MINSIZE, gui_base->get_theme_constant(SNAME("window_border_margin"), SNAME("Editor")));
				main_vbox->add_theme_constant_override("separation", gui_base->get_theme_constant(SNAME("top_bar_separation"), SNAME("Editor")));
				scene_root_parent->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("Content"), SNAME("EditorStyles")));
				bottom_panel->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("BottomPanel"), SNAME("EditorStyles")));
				tabbar_panel->add_theme_style_override("panel", gui_base->get_theme_stylebox(SNAME("tabbar_background"), SNAME("TabContainer")));
				scene_tabs->add_theme_constant_override("icon_max_width", gui_base->get_theme_constant(SNAME("class_icon_size"), SNAME("Editor")));
				scene_tab_add_ph->set_custom_minimum_size(scene_tab_add->get_minimum_size());
				main_menu->add_theme_style_override("hover", gui_base->get_theme_stylebox(SNAME("MenuHover"), SNAME("EditorStyles")));
			}
			scene_tabs->set_max_tab_width(int(EDITOR_GET("interface/scene_tabs/maximum_width")) * EDSCALE);
			_update_scene_tabs();