Don't hardcode the list of images in withRepository mixin

We could just iterate through the fields with `std.objectFields` and computing the new image names instead of having an explicit list of images.

Locate the withRepository mixin and read how its image fields are currently enumerated. Compare the existing image names with the fields exposed through std.objectFields, then verify that configuration generation still produces the same image names without an explicit list. Done means the mixin no longer hardcodes the image list and existing generated configuration remains unchanged.

Written by the indexing model from the issue text.