gh-110131: Keep one extend example

Author: v0ropaev

Doc/library/argparse.rst

@@ -823,15 +823,11 @@ how the command-line arguments should be handled. The supplied actions are:
   command line will be appended after those default values.
   Example usage::
 
-    >>> parser = argparse.ArgumentParser()
-    >>> parser.add_argument("--foo", action="extend", nargs="+", type=str)
-    >>> parser.parse_args(["--foo", "f1", "--foo", "f2", "f3", "f4"])
-    Namespace(foo=['f1', 'f2', 'f3', 'f4'])
     >>> parser = argparse.ArgumentParser()
     >>> parser.add_argument("--foo", action="extend", nargs="+", type=str,
     ...                     default=["d1"])
-    >>> parser.parse_args(["--foo", "f1", "f2"])
-    Namespace(foo=['d1', 'f1', 'f2'])
+    >>> parser.parse_args(["--foo", "f1", "--foo", "f2", "f3", "f4"])
+    Namespace(foo=['d1', 'f1', 'f2', 'f3', 'f4'])
 
   .. versionadded:: 3.8