should (according to the spec) write the property target when the bufferview is used for attributes or indices:
When a buffer view is used by vertex indices or attribute accessors it SHOULD specify bufferView.target with a value of element array buffer or array buffer respectively.
The function
https://github.com/jkuhlmann/cgltf/blob/561455ec216fa30d546854a2cb8c89b830b7b949/cgltf_write.h#L559-L570
should (according to the spec) write the property target when the bufferview is used for attributes or indices:
This is just an enhancement, not an error :)