pkg-config and pythonX.X-config not correctly installed by actions/setup-python?

Description:
I have a workflow that required building of shared libraries for OpenModelica that embed the Python interpreter. When using actions/setup-python to test this workflow, I don't seem to have a reliable way of detecting the configuration options for linking to libpython -- neither pkg-config nor python3.8-config (or whatever it is for the version of Python in question) seem to work reliably. What is the suggested approach?

Action version:
I'm using the current actions/setup-python@v2
See https://github.com/SolarTherm/SolarTherm/runs/4515306450?check_suite_focus=true for details.

Platform:

  • Ubuntu 20.04 and 18.04

Runner type:

  • Hosted

Tools version:
3.8 on 18.04
3.9 on 20.04
(see output at above link)

Repro steps:
See above link.

Expected behavior:
I would expect both pkg-config and python-config scripts to be provided. They don't seem to be.

Actual behavior:
Missing scripts/.pc files results in build errors.