CI: added windows client build, try 8

.github/workflows/build.yml

@@ -71,7 +71,7 @@ jobs:
         call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
         qmake --version
         qmake %GITHUB_WORKSPACE%/client/traintastic-client.pro CONFIG+="release" DESTDIR=${{runner.workspace}}/build
-        jom -j %NUMBER_OF_PROCESSORS% -f Makefile
+        nmake
         windeployqt --release --no-translations -no-system-d3d-compiler --no-opengl-sw traintastic-client.exe
 
   build-server: