### Godot version

0810ecaafdbee3ea747219e6ab3a8de5d2216a09

### System information

Windows 11, Nvidia 3000, firefox

### Issue description

Exporting the gltf file is corrupt in blender.

### Steps to reproduce

1. Open project.
2. Export as glb
3. Open in blender
4. Blender display many warnings

![image](https://user-images.githubusercontent.com/32321/216740742-de662c5c-f5c3-44b5-a36e-8ad33defdbba.png)


### Minimal reproduction project

https://cdn.discordapp.com/attachments/598003845657788438/1071249610896580691/Test_Game_Project.zip


skeleton_sets.create_union(parent, node_index);
			}
		}
		
		
		for (int i = 1; i < skin->roots.size(); ++i) {
			skeleton_sets.create_union(skin->roots[0], skin->roots[i]);
		}
	}
	{ 
		Vector<GLTFNodeIndex> groups_representatives;
		skeleton_sets.get_representatives(groups_representatives);
		Vector<GLTFNodeIndex> highest_group_members;
		Vector<Vector<GLTFNodeIndex>> groups;
		for (int i = 0; i < groups_representatives.size(); ++i) {
			Vector<GLTFNodeIndex> group;
			skeleton_sets.get_members(group, groups_representatives[i]);
			highest_group_members.push_back(_find_highest_node(p_state, group));
			groups.push_back(group);
		}
		for (int i = 0; i < highest_group_members.size(); ++i) {
			const GLTFNodeIndex node_i = highest_group_members[i];
			
			for (int j = i + 1; j < highest_group_members.size(); ++j) {
				const GLTFNodeIndex node_j = highest_group_members[j];
				
				if (p_state->nodes[node_i]->parent == p_state->nodes[node_j]->parent) {
					skeleton_sets.create_union(node_i, node_j);
				}
			}