Use cuda instead of cudatoolkit for cuda 11.6 (#77164)
Remove cudatoolkit dependency and as a resuld remove conda-forge depencency
Please refer to following job for cuda 11.6 workflow:
https://pipelines.actions.githubusercontent.com/serviceHosts/7d146c05-69c3-4c20-a0e7-818111670117/_apis/pipelines/1/runs/1996311/signedlogcontent/624?urlExpires=2022-05-11T15%3A20%3A49.2066302Z&urlSigningMethod=HMACV1&urlSignature=%2FxavsXyw5%2F0DCx%2FTGXrsP2kIM15TUELebxUOxRnE7%2B8%3D
Test PR: https://github.com/pytorch/pytorch/pull/79706
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77164
Approved by: https://github.com/malfet
