fix build for xfce and kde variant
    
    in cb7b538 Dusty moved repos from common to silverblue what was
    essentially partial revert 61d907b and therefore breaking xfce/kde
    builds. this fixes it by adding repos back
    
    (cherry picked from commit 9cb8e83eb2c1bca379e723e1e65ada6d6e43ab5f)