build for more dotnet versions

Author: jogibear9988

.github/workflows/dotnet.yml

@@ -19,8 +19,6 @@ jobs:
       uses: actions/setup-dotnet@v4
       with:
         dotnet-version: |
-           6.0.x
-           8.0.x
            9.0.x
     - name: Restore dependencies
       run: |