Install 'python3-scipy' on cloud runner

[t-kalinowski]

A recent reticulate submission surfaced a difference between the revdepcheck cloud runner and the actual Debian CRAN check machines: CRAN machines have 'scipy' installed, seemingly via apt install python3-scipy.

Via email from Kurt:

Tomasz Kalinowski writes:

Following up on this, I believe that our reverse dependency checks did
not catch the error from RcppArmadillo because
our runners do not have the "scipy" Python module pre-installed.

Is it documented what Python installations are available on the CRAN
machines? I.e., what versions of Python + packages, the type of Python
installation (system, venv, virtualenv, conda, or other), file path
locations where they are installed, and an approximate cadance they
are updated at?
A few minutes of googling didn't turn anything up for me.

Kurt Hornik writes:
Indeed, all my Debian check systems seem to have python3-scipy
installed. Not quite sure why: in principle things are made available
via our rcheckserver metapackage from our local Debian repository at
https://www.google.com/url?q=https://statmath.wu.ac.at/AASC/debian&source=gmail-imap&ust=1713769188000000&usg=AOvVaw1RlPhYgdxKPdTBQtp33Pmt, but whereas this depends on

$ apt-cache depends rcheckserver | grep python
Depends: ipython3
Depends: python3-dev
Depends: python3-mechanize
Depends: python3-numpy
Depends: python3-pygments
Depends: python3-pkg-resources

it does not seem to depend on python3-scipy ...