Increase package compatibility

[rubenvandeven]

Hi Kadirnar,
Thanks for implementing this tracker. Based on work in other forks, I made some changes to the package:

• Remove Pytorch dependency (this was done in a fork by @0xNOY)
• Changed the dependency on lap to lapx to have compatibility with python >= 3.10 (following the example of forks by @gimletlabs and @TomDarmon )
• Relaxed the dependence to improve package resolution in a larger project.
• I ran into an exception in update() when dets is an empy array/tensor.
• Fix issue A bug about initializing STrack bbox #2 by adding an xyxy2ltwh() function.

It would be nice to see these revisions upstreamed. Feel free to cherrypick.

[kadirnar]

I can't test it because I'm very busy. Did you test it?

[rubenvandeven]

Understandable! I do use this repo in my own code, so yes I did.
Important to note however that due to fixing #2 the coordinates are different that the original repo, in which the resulting bboxes were misaligned (the top left corner was at the detection's center). If one relies on exact position, that this can be considered a breaking change.