which executes pylicense with all configs matching
"PROJECT_ROOT/.pylicense*.cfg"

This is now mandatory to use in our modules instead of
```exclude_from_headercheck``` from dune-common. It must be used
_before_ calling ```BEGIN_TESTCASES```

This reverts commit 44df042c.
There was nothing to fix. We depend on using the right
branch in dune-testtools that has the additional argument.