Possible memory leak

[pnthai88]

I followed #51 and did reinstall Cython

pip uninstall cython
pip cache purge
pip install cython

Here is the 3.9.10 nogil from main branch, memory keep growing. I used gc.collect()

https://github.com/colesbury/nogil/assets/8721600/721b0689-4f1e-49af-88df-d53fd8b25d59

The same built from original version but with 3.11 official. Memory is very stable

https://github.com/colesbury/nogil/assets/8721600/f1981045-2545-4686-a22b-8b31e06601d4

My program quite simple. It fetch frame from FFMPEG, do some opencv preprocessing like resize, b64encode and send it to another server app.