Remove extension module build step in pyinstaller spec

@Vittorioux reported issues building with the newest version of setuptools, since v80.0 removed setuptools.sandbox and its run_setup function.
Reportedly, the build worked even after removing that part of the code. This commit makes that change.

Author: PhoenixBound

CoilSnake.spec

@@ -7,10 +7,6 @@ import shutil
 import sys
 import sysconfig
 
-from setuptools.sandbox import run_setup
-
-run_setup('setup.py', ['build_ext'])
-
 debug = False
 
 # This logic is specific to setuptools. It may change in future versions, as it did in 62.1.0.