The attached patch just moves the file without leaving an alias behind. It turns out we use this one in a fair few places (mostly for "assert_python_ok").

I'm going to sit on this change for the moment - after reading the docs, it's quite clear that the last couple of functions don't really belong in script_helper, but rather in the pkg_helper module discussed in issue 15376.

So my current plan is to factor that helper out *first*, then when this one lands, the intent of grouping more of the support code that folks working on the test suite might be interested in using together will hopefully be clearer.