Closes python#28713 uses OSError in the tutorial

Author: kushaldas

Doc/tutorial/errors.rst

@@ -174,7 +174,7 @@ example::
    for arg in sys.argv[1:]:
        try:
            f = open(arg, 'r')
-       except IOError:
+       except OSError:
            print('cannot open', arg)
        else:
            print(arg, 'has', len(f.readlines()), 'lines')