Remove support for installed `.egg` distributions

[Timothy Southwick]

Since updating to Python 3.12 and pip 24.0, installing packages through pip gives the following message:

DEPRECATION: Loading egg at /usr/lib/python3.12/site-packages/cupshelpers-1.0-py3.12.egg is deprecated. pip 24.3 will enforce this behaviour change. A possible replacement is to use pip for package installation.. Discussion can be found at https://github.com/pypa/pip/issues/12330
pypa/pip#12330