PEP 768: Fix a small typo (#4171)

Fix a small typo

peps/pep-0768.rst

@@ -147,7 +147,7 @@ provides Python code to be executed when the interpreter reaches a safe point.
 
 The value for ``MAX_SCRIPT_SIZE`` will be a trade-off between binary size and
 how big debugging scripts can be. As most of the logic should be in libraries
-and arbitrary code can be executed with very short ammount of Python we are
+and arbitrary code can be executed with very short amount of Python we are
 proposing to start with 4kb initially. This value can be extended in the future
 if we ever need to.