Issue #23356: Simplify convert_arg_line_to_args example.

Patch by py.user.
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index fd75cfe..9955646 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -1884,10 +1884,7 @@
    as an argument::
 
     def convert_arg_line_to_args(self, arg_line):
-        for arg in arg_line.split():
-            if not arg.strip():
-                continue
-            yield arg
+        return arg_line.split()
 
 
 Exiting methods