Fix build command in SonarQube workflow to specify solution file

Author: marcin-golebiowski

.github/workflows/test-windows.yml

@@ -43,5 +43,5 @@ jobs:
         shell: powershell
         run: |
           ${{ runner.temp }}\scanner\dotnet-sonarscanner begin /k:"SpiceSharp_SpiceSharpParser" /o:"spicesharp" /d:sonar.token="${{ secrets.SONAR_TOKEN }}"
-          dotnet build
+          dotnet build src/SpiceSharp-Parser.sln
           ${{ runner.temp }}\scanner\dotnet-sonarscanner end /d:sonar.token="${{ secrets.SONAR_TOKEN }}"