bug#35116: [PATCH staging] Add python-robotframework et al.

[T460s laptop]

I went ahead and pushed this series to staging (there was a requirement
on an updated python-requests that was present in staging but not in
master), after updating python-pygithub to its latest release and
adapting it a little bit so the tests could run successfully.

The commit at the top of the stack has the following hash: 73326e742d.

Closing.

Maxim