Update dotnet.yml

.github/workflows/dotnet.yml

@@ -29,11 +29,5 @@ jobs:
       # Add additional options to the MSBuild command line here (like platform or verbosity level).
       # See https://docs.microsoft.com/visualstudio/msbuild/msbuild-command-line-reference
       run: msbuild /m /p:Configuration=${{env.BUILD_CONFIGURATION}} ${{env.SOLUTION_FILE_PATH}}
-    - name: Setup .NET
-      uses: actions/setup-dotnet@v1
-      with:
-        dotnet-version: 3.1.100
-    - name: Build
-      run: dotnet build dirs.sln 
     - name: Test
       run: dotnet test dirs.sln --logger trx --verbosity normal