PMP::isotropic_remeshing() - Fix removal of boundary degenerate faces (2/2) (#8845)

## Summary of Changes

This PR follows #8685 and fixes issue #8836

Thanks @vegechick123 for the report!

## Release Management

* Affected package(s): PMP
* Issue(s) solved (if any): fix #8836
* License and copyright ownership: unchanged

Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/internal/Isotropic_remeshing/remesh_impl.h

@@ -1699,6 +1699,9 @@ private:
       {
         set_status(hf, MESH_BORDER); //only 1 or 2 of the listed halfedges
                                      //will survive face removal, but status will be correct
+        set_status(opposite(hf, mesh_), PATCH_BORDER); //idem
+                                     //some of them will not survive but setting status
+                                     //is cheaper then checking which should be set
       }
       CGAL::Euler::remove_face(h, mesh_);
     }