gh-141570: can_colorize: Expect fileno() to raise OSError, as documented (#141716)

In Fedora, we've been given a slightly incomplete reproducer for a problematic
Python 3.14 color-related change in argparse that leads to an exception when
Python is used from mod_wsgi: https://bugzilla.redhat.com/2414940

mod_wsgi replaces sys.stdout with a custom object that raises OSError on .fileno():

8460dbfcd5/src/server/wsgi_logger.c (L434-L440)

This should be supported, as the documentation of fileno explicitly says:

> An OSError is raised if the IO object does not use a file descriptor.

https://docs.python.org/3.14/library/io.html#io.IOBase.fileno

The previously expected exception inherits from OSError,
so it is still expected.

Fixes https://github.com/python/cpython/issues/141570

Co-authored-by: Cody Maloney <cmaloney@users.noreply.github.com>
Co-authored-by: Victor Stinner <vstinner@python.org>

Lib/test/test__colorize.py

@@ -166,6 +166,17 @@ def test_colorized_detection_checks_for_file(self):
                 file.isatty.return_value = False
                 self.assertEqual(_colorize.can_colorize(file=file), False)
 
+            # The documentation for file.fileno says:
+            # > An OSError is raised if the IO object does not use a file descriptor.
+            # gh-141570: Check OSError is caught and handled
+            with unittest.mock.patch("os.isatty", side_effect=ZeroDivisionError):
+                file = unittest.mock.MagicMock()
+                file.fileno.side_effect = OSError
+                file.isatty.return_value = True
+                self.assertEqual(_colorize.can_colorize(file=file), True)
+                file.isatty.return_value = False
+                self.assertEqual(_colorize.can_colorize(file=file), False)
+
 
 if __name__ == "__main__":
     unittest.main()