### 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.
#include "editor/plugins/node_3d_editor_plugin.h"
#include "editor/plugins/packed_scene_translation_parser_plugin.h"
#include "editor/plugins/root_motion_editor_plugin.h"
#include "editor/plugins/script_text_editor.h"
#include "editor/plugins/text_editor.h"
#include "editor/plugins/version_control_editor_plugin.h"
#include "editor/plugins/visual_shader_editor_plugin.h"
#include "editor/progress_dialog.h"
#include "editor/project_settings_editor.h"
#include "editor/register_exporters.h"
#include "editor/scene_tree_dock.h"
#include "editor/window_wrapper.h"
#include <stdio.h>
#include <stdlib.h>
EditorNode *EditorNode::singleton = nullptr;
static const String META_TEXT_TO_COPY = "text_to_copy";
static const String EDITOR_NODE_CONFIG_SECTION = "EditorNode";
void EditorNode::disambiguate_filenames(const Vector<String> p_full_paths, Vector<String> &r_filenames) {
	ERR_FAIL_COND_MSG(p_full_paths.size() != r_filenames.size(), vformat("disambiguate_filenames requires two string vectors of same length (%d != %d).", p_full_paths.size(), r_filenames.size()));
	
	
	Vector<RBSet<int>> index_sets;
	HashMap<String, int> scene_name_to_set_index;
	for (int i = 0; i < r_filenames.size(); i++) {
		String scene_name = r_filenames[i];
		if (!scene_name_to_set_index.has(scene_name)) {
			index_sets.append(RBSet<int>());
			scene_name_to_set_index.insert(r_filenames[i], index_sets.size() - 1);
		}
		index_sets.write[scene_name_to_set_index[scene_name]].insert(i);