Replace gnome-shell-extension-pomodoro by gnome-pomodoro
    
    This commit addresses the change from upstream renaming gnome-shell-extension-pomodoro
    to gnome-pomodoro.
    See https://src.fedoraproject.org/rpms/gnome-pomodoro/blob/rawhide/f/gnome-pomodoro.spec
    
    Signed-off-by: Luya Tshimbalanga <luya@fedoraproject.org>