Bump VERSION_PREFIX to 1.2 in CI workflow

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: sebgod

.github/workflows/dotnet.yml

@@ -7,7 +7,7 @@ on:
     branches: [ main ]
 
 env:
-  VERSION_PREFIX: 1.1.${{ github.run_number }}
+  VERSION_PREFIX: 1.2.${{ github.run_number }}
   VERSION_REV: ${{ github.run_attempt }}
   VERSION_HASH: +${{ github.sha }}
   BUILD_CONF: Release