test: use range() to shorten test_sunday_ranges_to

[bdrung]

Use range() to shorten test_sunday_ranges_to.

The other tests can be shortened as well. Example:

        self._test_sunday_ranges(
            "0 0 * * Thu-Sun",
            list(range(4, 8))
            + list(range(11, 15))
            + list(range(18, 22))
            + list(range(25, 29))
            + list(range(1, 4))
            + list(range(8, 12))
            + list(range(15, 19))
            + list(range(22, 23)),
        )

But I do not know if that is better to read.