spec file: do not use nodejs-22 on f39 and f40
    
    Nodejs22 has been released on f39 and f40 and freeipa fails
    to build with this version. Nodejs22 will be the default version
    in f41+ and adds a symlink from /usr/bin/node-22 to /usr/bin/node
    but on older fedora versions, the symlink is not created.
    As our build is using /usr/bin/node command, it fails with
    command not found.
    
    Stick to Nodejs 20 on these older versions.
    
    Fixes: https://pagure.io/freeipa/issue/9643
    
    Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>