refactor: update Xcode version to 26.2-beta in release workflow

Author: euxx

.github/workflows/release.yml

@@ -23,7 +23,7 @@ jobs:
       - name: Select Xcode version
         uses: maxim-lobanov/setup-xcode@v1
         with:
-          xcode-version: latest-stable
+          xcode-version: 26.2-beta
 
       - name: Build VolumeGrid
         shell: bash