remove un-needed dependencies from crabtaskworker-pypi

[belforte]

it currently takes O(10) min to build TW container in the pipeline.
I think it is because we still have a list of dependencies from "old rpm times" with all possible things used by all possible WMCore application in https://github.com/dmwm/CRABServer/blob/master/cicd/crabtaskworker_pypi/requirements.txt
Already https://github.com/dmwm/CRABServer/blob/master/cicd/crabserver_pypi/requirements.txt is much more trimmed.

[novicecpp]

Thanks Stefano.
From what I saw in CI machine, most CPU is gone due to I/O wait. Reducing the deps will help cutting time by a lot.

[belforte]

yeah, I had been looking at pipeline log in realtime and noticed that all those pip install were taking a lot.
I built pypi-test2-reducetwdep with that and at least TW is built in same time as server. A lot of time goes in conda/gfal as you know. I guess the only way to cut time now is to create a base image with gfal and start from that. Not sure it is worth