Base pipelines are used to optimize the vulkan pipeline creation.
Instead of building each pipeline from scratch a base pipeline can
be used to share resources and faster code-paths.
We used to overwrite the base pipeline with the last created pipeline.
This PR doesn't overwrite the base pipeline after it was initially set
giving less confusion when working with base pipelines.
Pull Request: https://projects.blender.org/blender/blender/pulls/127181
52a84b6c01