XPK dependency installation is hard on TPU VM

[gobbleturk]

I wrote my own hacky instructions for installing XPK dependencies on a TPU VM (e.g. v6e) here with the help of a permissions guru @lukebaumann

[lukebaumann]

2 cents: The main issue covered in the link is installing an unmanaged version of gcloud which may only be a problem when running XPK from a GCE instance.

[tengyifei]

IMO things will be much smoother if we can vendor all the binary dependencies in xpk. That will also solve problems where xpk wants a specific version of a dependency instead of whatever the user has installed.