Fix indentation

Author: AnnaMastori

lib/matplotlib/tests/test_compare_images.py

@@ -43,7 +43,7 @@
         ('all128.png', 'all127.png', 0, 1),
     ])
 def test_image_comparison_expect_rms(im1, im2, tol, expect_rms, tmp_path,
-                                                            monkeypatch):
+                                     monkeypatch):
     """
     Compare two images, expecting a particular RMS error.