Update to pyproject.toml

[c0nb4]

Currently during installation the following DEPRECATIOn info occurs:

(vDistrict) C:\Users\Programmieren\SRI-ADE\vDistrict\djangoCityDB>pip install -e C:\Users\felix\Programmieren\SRI-ADE\vDistrict\djangoCityDB
Obtaining file:///C:/Users//Programmieren/SRI-ADE/vDistrict/djangoCityDB
Preparing metadata (setup.py) ... done
Installing collected packages: django-citydb
DEPRECATION: Legacy editable install of django-citydb==0.1.0 from file:///C:/Users//Programmieren/SRI-ADE/vDistrict/djangoCityDB (setup.py develop) is deprecated. pip 25.1 will enforce this behaviour change. A possible replacement is to add a pyproject.toml or enable --use-pep517, and use setuptools >= 64. If the resulting installation is not behaving as expected, try using --config-settings editable_mode=compat. Please consult the setuptools documentation for more information. Discussion can be found at pypa/pip#11457
Running setup.py develop for django-citydb

Switch to pyproject.toml to avoid this