Migrating from s2clientprotocol to pys2clientprotocol

[maxnus]

As discussed on Discord, I made a package with prebuilt _pb2.py files, using protobuf >= 6:

• https://github.com/maxnus/py-s2client-proto
• https://pypi.org/project/pys2clientprotocol/

The package comes with *.pyi stubs so we could also remove them from this repo.

edit: I think the failures are just because I pushed too quickly after releasing 1.0.1; rerunning the pipeline should fix it

[BurnySc2]

Works on my PC (linux+WINE).
I couldn't verify the performance improvements though.

The github actions runners seem to show some improvements in their runtime. It may be because of this change.
Testsuite + docker runner: down from 35 to 18 minutes
New docker image creation: down from 15 to roughly 10 minutes

35 minutes: https://github.com/BurnySc2/python-sc2/actions/runs/22142367633?pr=235
down to 18 minutes: https://github.com/BurnySc2/python-sc2/actions/runs/22142367633?pr=235

15 minutes: https://github.com/BurnySc2/python-sc2/actions/runs/22142367656?pr=235
down to 10 minutes: https://github.com/BurnySc2/python-sc2/actions/runs/23719272754?pr=239