Previously, when a file output test failed, all images within the same test case were updated, even images that did not cause the test to fail. This patch only updates changed/removed images so when the test is run using `BLENDER_TEST_UPDATE=1 ctest -R compositor_cpu_file_output` git will only show the modified, added or removed images Pull Request: https://projects.blender.org/blender/blender/pulls/134852