style: format code with Black and isort (#133)

This commit fixes the style issues introduced in de519b4 according to the output
from Black and isort.

Details: None

Co-authored-by: deepsource-autofix[bot] <62050782+deepsource-autofix[bot]@users.noreply.github.com>

epub_image_optimizer/image_optimizer.py

@@ -8,7 +8,7 @@
 from typing import List, Tuple
 
 import tinify
-from lxml.etree import fromstring, HTMLParser, parse
+from lxml.etree import HTMLParser, fromstring, parse
 from PIL import Image
 from rich.progress import Progress, TaskID