Update citation file

Author: glatterf42

CITATION.cff

@@ -8,9 +8,9 @@ message: >-
   the GitHub repository and the MESSAGEix framework manuscript 
   (https://doi.org/10.1016/j.envsoft.2018.11.012).
 type: software
-version: 3.10.0
+version: 3.11.0
 # Format: "yyyy-mm-dd"
-date-released: "2025-02-19"
+date-released: "2025-05-26"
 authors:
   - given-names: Paul Natsuo
     family-names: Kishimoto