install Go 1.13 on windows

tools/internal_ci/helper_scripts/prepare_build_windows.bat

@@ -35,6 +35,10 @@ python -m pip install google-api-python-client
 powershell -File src\csharp\install_dotnet_sdk.ps1
 set PATH=%LOCALAPPDATA%\Microsoft\dotnet;%PATH%
 
+@rem Newest version of Go is required to be able to build boringssl with cmake
+@rem TODO(jtattermusch): try to eliminate the dependency on Go
+choco install golang -y --version 1.13.1 --limit-output
+
 @rem Disable some unwanted dotnet options
 set NUGET_XMLDOC_MODE=skip
 set DOTNET_SKIP_FIRST_TIME_EXPERIENCE=true