#621 Please add Unsloth Qwen3.8-Flash-Next-UD-IQ4_XS

Beschreibung

Please add model Unsloth Qwen3.8-Flash-Next-UD-IQ4_XS

Reason:  model UD-Q4_K_XL is too big.  IQ3_S is fast but much dumber.  We need something in the middle ground, such as UD-IQ4_XS .  It makes a huge difference.