Then maybe Procrastinate (https://procrastinate.readthedocs.io/en/main/) is something for you (I just contributed some features to it). It has very good documentation, MIT license, and also some nice features like job scheduling, priorities, cancellation, etc.
Mantine version 5 was just released some days ago. I am not the creator, but just an admirer and made some small contributions. Full changelog can be found here: https://mantine.dev/changelog/5-0-0/