Publish alpha release for pyPI

[LeonardHd]

We want to publish the pyPI package indicating it is a alpha release for now.

The Version specifiers based on (PEP 440) see Python Packaging User Guide requires us to use a releases that MUST be numbered in a consistently increasing fashion, otherwise automated tools will not be able to upgrade them correctly.

As such we would like to publish for now in a X.YaN which indicates an alpha release and keep options open to adopt semantic versioning, etc. later one.

The easiest and a consistent approach is to use 0.0.0.a${{ github.run_number}} for now, and evolve from there.