### 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 (a.has(gltf_texcoord_key)) {
					texcoord_second = _decode_accessor_as_vec2(p_state, a[gltf_texcoord_key], true);
					num_channels = 4;
				}
				if (!num_channels) {
					break;
				}
				if (num_channels == 2 || num_channels == 4) {
					cur_custom.resize(vertex_num * num_channels);
					for (int32_t uv_i = 0; uv_i < texcoord_first.size() && uv_i < vertex_num; uv_i++) {
						cur_custom.write[uv_i * num_channels + 0] = texcoord_first[uv_i].x;
						cur_custom.write[uv_i * num_channels + 1] = texcoord_first[uv_i].y;
					}
					
					for (int32_t uv_i = texcoord_first.size(); uv_i < vertex_num; uv_i++) {
						cur_custom.write[uv_i * num_channels + 0] = 0;
						cur_custom.write[uv_i * num_channels + 1] = 0;
					}
				}
				if (num_channels == 4) {
					for (int32_t uv_i = 0; uv_i < texcoord_second.size() && uv_i < vertex_num; uv_i++) {
						
						cur_custom.write[uv_i * num_channels + 2] = texcoord_second[uv_i].x;
						cur_custom.write[uv_i * num_channels + 3] = texcoord_second[uv_i].y;
					}
					
					for (int32_t uv_i = texcoord_second.size(); uv_i < vertex_num; uv_i++) {
						cur_custom.write[uv_i * num_channels + 2] = 0;
						cur_custom.write[uv_i * num_channels + 3] = 0;
					}