Replace isort with ruff

kitty_tests/diff.py

@@ -22,7 +22,7 @@ class TestDiff(BaseTest):
                 self.assertEqual((prefix, suffix), (src[:pc], src[-sc:] if sc else ''))
 
     def test_split_with_highlights(self):
-        from kittens.diff.render import split_with_highlights, Segment, truncate_points
+        from kittens.diff.render import Segment, split_with_highlights, truncate_points
         self.ae(list(truncate_points('1234567890ab', 3)), [3, 6, 9])
         for line, width, prefix_count, suffix_count, expected in [
                 ('abcdefgh', 20, 2, 3, ('abSScdeEEfgh',)),
@@ -45,8 +45,9 @@ class TestDiff(BaseTest):
         self.ae(['S1SaE1ES2SbcE2Ed'], split_with_highlights('abcd', 10, highlights))
 
     def test_walk(self):
-        from pathlib import Path
         import tempfile
+        from pathlib import Path
+
         from kittens.diff.collect import walk
 
         with tempfile.TemporaryDirectory() as tmpdir: