refactor(objects module def): remove redundant subclass discovery code

With the automated subclass registry, there is no need for the magic module lookup in objects
__init__

speckle/objects/__init__.py

@@ -1,14 +1,5 @@
-from pathlib import Path
-import sys
-import inspect
-import pkgutil
-from importlib import import_module
-from .base import Base
+"""Builtin Speckle object kit."""
 
+from  speckle.objects.base import Base
 
-for (_, name, _) in pkgutil.iter_modules([Path(__file__).parent]):
-    imported_module = import_module("." + name, package=__name__)
-    classes = inspect.getmembers(imported_module, inspect.isclass)
-    for c in classes:
-        if issubclass(c[1], Base):
-            setattr(sys.modules[__name__], c[0], c[1])
+__all__ = ["Base"]