You can also write a custom transformer which is very easy:
class Resize:
    def __init__(self, size):
        assert isinstance(size, int) or (isinstance(size, Iterable) and len(size) == 2)
        if isinstance(size, int):
            self._size = (size, size)
        else:
            self._size = size

    def __call__(self, img: np.ndarray):
        resize_image = skimage.transform.resize(img, self._size)
        # the resize will return a float64 array
        return skimage.util.img_as_ubyte(resize_image)