Batches don't always provide all required resources for a shader.
This can happen when the resource is defined in the shader, but
not used in a specific variant. The definition is still there and
needs to be filled.
This PR adds a dummy buffer to fill the missing attributes.
It also fixes an issue when using vertex attributes that
uses multiple binding locations (mat4).
Pull Request: https://projects.blender.org/blender/blender/pulls/111350
4ebd7d84d1