Update build-test.yaml

Author: prochnowc

.github/workflows/build-test.yaml

@@ -30,7 +30,10 @@ jobs:
         with:
           dotnet-version: |
             8.0.x
-            9.0.x
+            9.0.x      
+      - name: Set BUILD_CONFIGURATION
+        if: startsWith(github.ref, 'refs/tags/')
+        run: echo "BUILD_CONFIGURATION=Release" >> $GITHUB_ENV
       - name: Restore
         run: dotnet restore
       - name: Build