Update build.yml (#465)

Author: ardalis

.github/workflows/build.yml

@@ -18,9 +18,9 @@ jobs:
       uses: actions/setup-dotnet@v3
       with:
           dotnet-version: |
-            '6.x'
-            '7.x'
-            '8.x'
+            6.0.x
+            7.0.x
+            8.0.x
     - name: Install dependencies
       run: dotnet restore
     - name: Build