Use dbx_py_binary for running vpip

[jsharpe]

This ensures that the dependencies installed via vpip are using the correct version of python as the version of python configured in the rules_python toolchain may be different to that used by the dbx_py_binary rules.

[jsharpe]

I actually ran into a need to also run vinst as a dbx_py_binary rule as well but IIRC this caused circular dependency issues. @jhance I'm guessing you don't run into this internally because you build python as a binary separately and make that built binary available on PATH to bazel when building other tooling if I'm not mistaken. In my case I am building python and using libraries against it within the same build.

[jsharpe]

@jhance friendly ping on this.

[jhance]

5047bda covered this it seems.

[jsharpe]

Yes, it does; although technically vinst should also run through dbx_py_binary too but I couldn't get this to work due to a circular dep. Not sure if this has changed now but we've largely moved over to rules_python now instead of these rules due to them becoming unmaintained in the OSS version for a long enough period.

[jhance]

Yeah, unfortunately its not really an official project to maintain this repository and at some point the tooling we added to ensure that the repository is actually exportable with the copybara patches got turned off, which resulted in it being quite the headache to be able to export again.