cone_2p ZeroDivisionError: float division

[AGeissler]

Describe the bug
ZeroDivisionError: float division from cone_2p when apex has smaller z than base.

To Reproduce

1. A simplified Python script which triggers the error.
   base_test=[ 6.275 , 13.8 , 3.07673913]
   apex_test=[ 6.275 , 13.8 , 2.77673913]
   from ezdxf.render import forms
   cone = forms.cone_2p(16, 0.1, base_test, apex_test)

2. Information about the ezdxf version and the OS.
   ezdxf 1.0.0, render.py updated to last commit (Dec. 26). MacOS 12.6.2.

3. If a 3rd party DXF file causes the error, add a simplified and zipped
   DXF file which still triggers the error.
   N.A.

Expected behavior
Generation of a cone pointing downwards in WCS.

Screenshots
N.A.