gh-106318: Remove an example from str.startswith() method documentation

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

Author: adorilson

Doc/library/stdtypes.rst

@@ -2741,8 +2741,6 @@ expression support in the :mod:`re` module).
 
       >>> 'Python'.startswith('Py')
       True
-      >>> 'a tuple of prefixes'.startswith(('at', 'in'))
-      False
       >>> 'a tuple of prefixes'.startswith(('at', 'a'))
       True
       >>> 'Python is amazing'.startswith('is', 7)