Prefer newer versions of Python
Prefer newer versions of Python

Some formulae declare multiple Python dependencies, and they can appear
in any order in the `deps` array. Let's make sure to prefer the newest
one when adding their `libexec/"bin"` directory to `PATH`.

MikeMcQuaid/brew,nandub/brew,nandub/brew,MikeMcQuaid/brew,JCount/brew,nandub/brew,JCount/brew,MikeMcQuaid/brew,Homebrew/brew,Homebrew/brew,MikeMcQuaid/brew,nandub/brew,Homebrew/brew,JCount/brew,JCount/brew,Homebrew/brew