codemirror: update Codemirror to 5.13.4
This is newer codemirror with support to jump to line keybinding https://github.com/codemirror/CodeMirror/issues/3030
/cc @isabelle I don't know if this interfere with 53a4b813
This is newer codemirror with support to jump to line keybinding https://github.com/codemirror/CodeMirror/issues/3030
/cc @isabelle I don't know if this interfere with 53a4b813