[vulkan] Remove dead code from previous Vulkan backend (#73243)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73243
The previous version of the Vulkan backend is no longer being used anymore. Delete the dead code from the codebase.
Test Plan: Make sure everything still builds.
Reviewed By: beback4u
Differential Revision: D34400045
fbshipit-source-id: ae2a61452bf9199c11d81cc0369de8a9dd6692b1
(cherry picked from commit 22ee917f05f36ed16226dbe79da7892426eb09a2)
