Remove do_egg_install (unused).

Author: jaraco

setuptools/command/install.py

@@ -126,9 +126,6 @@ def _called_from_setup(run_frame):
 
         return False
 
-    def do_egg_install(self) -> None:
-        raise NotImplementedError("Support for egg-based install has been removed.")
-
 
 # XXX Python 3.1 doesn't see _nc if this is inside the class
 install.sub_commands = [