librttopo: add geospatial team to maintainers

pkgs/development/libraries/librttopo/default.nix

···
     description = "RT Topology Library";
     homepage = "https://git.osgeo.org/gitea/rttopo/librttopo";
     license = licenses.gpl2Plus;
-    maintainers = with maintainers; [ dotlambda ];
+    maintainers = with maintainers; teams.geospatial.members ++ [ dotlambda ];
     platforms = platforms.unix;
   };
 }