Remove reference to micropython-lib

Author: RetiredWizard

docs/library/sys.rst

@@ -27,8 +27,7 @@ Functions
       ``traceback`` module in CPython. Unlike ``traceback.print_exception()``,
       this function takes just exception value instead of exception type,
       exception value, and traceback object; *file* argument should be
-      positional; further arguments are not supported. CPython-compatible
-      ``traceback`` module can be found in `micropython-lib`.
+      positional; further arguments are not supported.
 
 Constants
 ---------