Update build.yml

Author: lvukadinovic-ib

.github/workflows/build.yml

@@ -13,7 +13,10 @@ jobs:
     - name: Setup .NET
       uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: ${{ matrix.dotnet-version }}
+        dotnet-version: |
+          6.x
+          7.x
+          8.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build