python.pkgs.spyder: remove maintainers

since we both do not use this package anymore.
cc @bjornfor

pkgs/applications/science/spyder/default.nix

···
     homepage = https://github.com/spyder-ide/spyder/;
     license = licenses.mit;
     platforms = platforms.linux;
-    maintainers = with maintainers; [ bjornfor fridh ];
   };
 }