cgi is deprecated in Python 3.12

[YtvwlD]

Running labello with Python 3.12 gives the following warning:

DeprecationWarning: 'cgi' is deprecated and slated for removal in Python 3.13

[YtvwlD]

Running this on Python 3.13 gives:

Traceback (most recent call last):
File "/app/labelprinterServe.py", line 9, in
import cgi
ModuleNotFoundError: No module named 'cgi'

We could probably use https://pypi.org/project/legacy-cgi/