fix Docker image for building a wheel

devscripts/files/Dockerfile.wheel

@@ -12,7 +12,7 @@ ADD requirements/requirements-dist.txt ./
 RUN pip install -r requirements-dist.txt
 
 # Add files necessary to build the wheel
-ADD LICENSE MANIFEST.in README.md setup.py pyproject.toml ./
+ADD LICENSE MANIFEST.in README.md pyproject.toml ./
 ADD docs/source/intro.rst docs/source/
 ADD ca/django_ca ca/django_ca