Correct CHANGELOG date

Author: Joao-Dionisio

CHANGELOG.md

@@ -27,7 +27,7 @@
 - changed addConsNode() and addConsLocal() to mirror addCons() and accept ExprCons instead of Constraint
 ### Removed
 
-## 6.0.0 - 2025.xx.yy
+## 6.0.0 - 2025.11.28
 ### Added
 - Support for SCIP 10.0.0
 - Added support for IIS - Irreducible Inconsistent Subsystems