Fix vague introduction.

Author: ZeroIntensity

peps/pep-0788.rst

@@ -16,7 +16,7 @@ Abstract
 :c:func:`PyGILState_Ensure`, :c:func:`PyGILState_Ensure`, and other related
 functions in the ``PyGILState`` family are the most common way to create
 native threads that interact with Python. They have been the standard for over
-twenty years (:pep:`311`). But, as Python has grown, these functions have
+twenty years (:pep:`311`). But, over time, these functions have
 become problematic:
 
 - They aren't safe for finalization, either causing the calling thread to hang or