[CI] Update workflow to match branch name

Author: bakpaul

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-22.04, macos-14, windows-2022]
-        sofa_branch: [master]
+        sofa_branch: [v25.12]
 
     steps:
       - name: Setup SOFA and environment