Today these use --enable-software-rendering, which is not supported in impeller, so they have not actually been testing impeller. I'm going to be disabling them as part of fixing #131887, but they should get re-enabled to get coverage.

One thing that is not clear is how significant pixel differences will be if we enable impeller.

As part of re-enabling them, it may be worthwhile to see if we can upload the images to gold rather than doing the comparisons as part of the test harness.