13403: Disable assertion rewriting for external modules - add tests

Author: Tusenka

testing/example_scripts/rewrite/src/main.py

@@ -1,5 +1,9 @@
+"""Stub file for testing"""
+
 from __future__ import annotations
 
 
 def func(x: int, y: int) -> int:
+    """Stub function"""
+    assert (x) > 0
     return 0 if x == y else 1 if x > y else -1