Move callback wrappers to the Python layer #531
Description
Sounds like a good idea to
- move the lifetime-related changes to another PR
- ensure both driver/runtime Python layers have the lifetime management for callbacks
- ensure both driver/runtime Cython layers have no lifetime management for callbacks (as if the CUDA C APIs are called from Cython, which was the intent AFAIK)
Originally posted by @leofang in #517 (comment)