Multiple previous changes made resource pools obsolete. Resource
pools were used to keep track of resources when the frame is rendered.
Multiple frames can be rendered at the same time and resources could
overlap.
This has been replaced (not this commit) to be part of the render graph
and when an submission has completed the resources are recycled.
Continuation of: https://projects.blender.org/blender/blender/pulls/145408
Pull Request: https://projects.blender.org/blender/blender/pulls/145511
dfd168f905