### 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


if (!p_state->json.has("materials")) {
		return OK;
	}
	const Array &materials = p_state->json["materials"];
	for (GLTFMaterialIndex i = 0; i < materials.size(); i++) {
		const Dictionary &d = materials[i];
		Ref<StandardMaterial3D> material;
		material.instantiate();
		if (d.has("name") && !String(d["name"]).is_empty()) {
			material->set_name(d["name"]);
		} else {
			material->set_name(vformat("material_%s", itos(i)));
		}
		material->set_flag(BaseMaterial3D::FLAG_ALBEDO_FROM_VERTEX_COLOR, true);
		Dictionary pbr_spec_gloss_extensions;
		if (d.has("extensions")) {
			pbr_spec_gloss_extensions = d["extensions"];
		}
		if (pbr_spec_gloss_extensions.has("KHR_materials_pbrSpecularGlossiness")) {
			WARN_PRINT("Material uses a specular and glossiness workflow. Textures will be converted to roughness and metallic workflow, which may not be 100% accurate.");