Adjust ptxas search path priorities
Adjust ptxas search path priorities

When looking for ptxas and other NVIDIA binary tools we go through a list of potential locations until we find a suitable version of ptxas.

Changing this list or its order has been deemed difficult in the past because there are many users out there that rely on the fact that this list happens to choose the right binary for them.

So this is making a careful change that is only affecting Google environments and makes no change to any OSS build of TF, JAX or XLA.
