testing: Fix installation of swid-generator with newer versions of setuptools

testing: Fix installation of swid-generator with newer versions of setuptools

With version 60.0.0 setuptools changed to a local installation of
distutils.  This seems to break the installation of swid-generator (causing
an `importlib.metadata.PackageNotFoundError: swid-generator` error).

Note that while Debian ships setuptools 52.0.0, `python-daemon` recently
added a dependency on `setuptools>=62.4.0`, which installs that version
that's then later used to install swid-generator.

The main difference seems to be that the local version installs the
package in `/usr/lib/python3.9/site-packages`, while the stdlib version
does so in `/usr/local/lib/python3.9/dist-packages` (similarly for the
`swid_generator` script and the `distro` dependency).

Not sure if there is a better/proper way to fix this.  Might just be an
issue with Debian bullseye and mixing system packages with those installed
via pip3.