dev(narugo): add test for align_maxsize

def align_maxsize(image: ImageTyping, max_size: int) -> Image.Image:

    """

    Resizes the image while maintaining its aspect ratio, ensuring that the length of its longer side

    does not exceed the specified maximum size.

    aligns with the given ``max_size``.

    :param image: The input image to be resized.

    :param max_size: The maximum length of the longer side after resizing.

import pytest

from PIL import Image

from imgutils.operate import align_maxsize

from test.testings import get_testfile

@pytest.fixture()

def genshin_post() -> Image.Image:

    return Image.open(get_testfile('genshin_post.jpg'))

@pytest.mark.unittest

class TestOperateAlign:

    def test_align_maxsize(self, genshin_post, image_diff):

        assert genshin_post.size == (1280, 720)

        _origin_mode = genshin_post.mode

        new_img1 = align_maxsize(genshin_post, 800)

        assert new_img1.size == (800, 450)

        assert new_img1.mode == _origin_mode

        assert image_diff(

            genshin_post.resize((800, 450)).convert('RGB'),

            new_img1.convert('RGB'),

            throw_exception=False

        ) < 1e-2

        new_img2 = align_maxsize(genshin_post, 2000)

        assert new_img2.size == (2000, 1125)

        assert new_img2.mode == _origin_mode

        assert image_diff(

            genshin_post.resize((2000, 1125)).convert('RGB'),

            new_img2.convert('RGB'),

            throw_exception=False

        ) < 1e-2