workflows/run-pytests.yml: Run Python unit tests
workflows/run-pytests.yml: Run Python unit tests

Adds Python unit tests to the CI. Explicitly enabled for each project
and the nmigen_cfu directory.

Signed-off-by: Alan Green <97e77871b5fcc4941bebceb4338c97c1fd149f8c@google.com>

google/CFU-Playground,google/CFU-Playground,google/CFU-Playground,google/CFU-Playground