[clang] [llvm] [Clang] Add env var for nvptx-arch/amdgpu-arch timeout (PR #102521)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

Also, just be aware that if you set this, it will apply to everything. So if you had a particularly long link job, probably would be a good idea to make it wait forever.

https://github.com/llvm/llvm-project/pull/102521