### Godot version

v4.0.beta.custom_build [fab9926a9]

### System information

Fedora 37

### Issue description

When creating a new inherited scene, saving the scene (for example with Ctrl+S) defaults to overwriting the scene being inherited, instead of prompting for a location to save to.

### Steps to reproduce

1. Create a new inherited scene
2. Press Ctrl+S

If the scene being inherited is imported (for example from a glTF), an error displays. If the inherited scene is a .tscn or .scn, it gets overridden by an inherited scene that tries to inherit itself, which is impossible and thus corrupt.

### Minimal reproduction project

N/A
unr.size -= Vector2(4, 7);
	dock_select->draw_rect(unr, unusable);
	dock_tab_move_left->set_disabled(true);
	dock_tab_move_right->set_disabled(true);
	if (dock_popup_selected_idx != -1 && dock_slot[dock_popup_selected_idx]->get_tab_count()) {
		dock_tab_move_left->set_disabled(dock_slot[dock_popup_selected_idx]->get_current_tab() == 0);
		dock_tab_move_right->set_disabled(dock_slot[dock_popup_selected_idx]->get_current_tab() >= dock_slot[dock_popup_selected_idx]->get_tab_count() - 1);
	}
	for (int i = 0; i < DOCK_SLOT_MAX; i++) {
		Vector2 ofs;
		switch (i) {
			case DOCK_SLOT_LEFT_UL: {
			} break;
			case DOCK_SLOT_LEFT_BL: {
				ofs.y += s.y;
			} break;
			case DOCK_SLOT_LEFT_UR: {
				ofs.x += s.x;
			} break;
			case DOCK_SLOT_LEFT_BR: {
				ofs += s;
			} break;
			case DOCK_SLOT_RIGHT_UL: {
				ofs.x += s.x * 4;
			} break;
			case DOCK_SLOT_RIGHT_BL: {
				ofs.x += s.x * 4;
				ofs.y += s.y;
			} break;
			case DOCK_SLOT_RIGHT_UR: {