Make old_gpu warning dynamic (#56621)
Summary:
Compute minimum support CUDA architecture as oldest GPU arch_list
supported by current build
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56621
Reviewed By: soumith
Differential Revision: D27920141
Pulled By: malfet
fbshipit-source-id: 71a42dd60c38a658ebad4544bcfb3d2d20e471b5
