The webkitgtk package will be removed from rawhide after Fedora 26 is branched due to the high number of unfixed security vulnerabilities. You must remove this dependency or your package will not be present in Fedora 27. Please refer to [1] for a FAQ on this matter and be advised that for some packages this may require a substantial amount of work. Note: if webkit-sharp is a bindings package specifically intended to provide WebKit1 or GTK+ 2 bindings, then it can safely be retired. [1] https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/AKVB363GFCHHJ5MTHGVYHYT6NLLTF5VM/
webkit-sharp is indeed webkit1 *and* GTK+2 specific. There are two other projects, neither of which are packaged with fedora, that provides later support. https://github.com/hbons/webkit2-sharp - webkit2 + GTK3 https://github.com/openmedicus/webkitgtk3-sharp - webkit1 + GTK3 There is no webkit2 + GTK2 binding, AFAIK.
OK, let's close this as WONTFIX then, nothing to be done here except retire the package after F26 is branched.