Update sponsors.yaml

Author: alexeygrigorev

_data/sponsors.yaml

@@ -5,12 +5,6 @@
   from: 2025-01-01 00:00:00
   to: 2026-01-01 00:00:00
 
-- name: "dstack"
-  link: https://dstack.ai/
-  image: /images/partners/dstack.svg
-  from: 2025-01-01 00:00:00
-  to: 2026-01-01 00:00:00
-
 - name: "Astronomer"
   link: https://www.astronomer.io/
   image: /images/partners/astronomer.png