remove commented out assertions file (#8388)

Author: TomeHirata

dspy/primitives/__init__.py

@@ -1,12 +1,10 @@
-from dspy.primitives import assertions
 from dspy.primitives.example import Example
 from dspy.primitives.module import BaseModule
 from dspy.primitives.prediction import Completions, Prediction
 from dspy.primitives.program import Module, Program
 from dspy.primitives.python_interpreter import PythonInterpreter
 
 __all__ = [
-    "assertions",
     "Example",
     "BaseModule",
     "Prediction",