I took a photograph with an iPhone 11 which has a light sensor issue. Due to that, the photograph is purple-ish and has a strange line in the top. Part of the photograph (the sky) depicting the phenomenon is shown below (I will not post here the whole photograph for privacy reasons):
By using phone's photograph editor I can in some way correct the color, but I cannot remove the line (see picture below). Do you know any simple tool that could easily remove such line (there is, for instance, Photoshop, but I would rather prefer to use an open-source software or one imbedded into a web browser)?