This patch improves the interactivity of the GPU compositor for
interactive node tree edits by waiting on GPU work to finish to support
more granular canceling.
This does have a performance penalty, but it does not affect final
rendering and it seems worth it because even though it is slower it will
feel faster for users.
Pull Request: https://projects.blender.org/blender/blender/pulls/120656
2cf8b5c4e1