Flip the installation order of Python38 and Golang

tools/internal_ci/helper_scripts/install_python38.ps1

@@ -28,7 +28,7 @@ function Install-Python {
     Write-Host "Python installer $PythonInstallerPath validated."
 
     # Installs Python
-    & $PythonInstallerPath /passive InstallAllUsers=1 PrependPath=1 Include_test=0 TargetDir=$PythonInstallPath
+    & $PythonInstallerPath /quiet InstallAllUsers=1 PrependPath=1 Include_test=0 TargetDir=$PythonInstallPath
     if (-Not $?) {
         throw "The Python installation exited with error!"
     }

tools/internal_ci/helper_scripts/prepare_build_windows.bat

@@ -35,13 +35,13 @@ python -m pip install google-api-python-client
 powershell -File src\csharp\install_dotnet_sdk.ps1
 set PATH=%LOCALAPPDATA%\Microsoft\dotnet;%PATH%
 
-@rem Install Python 3.8.0
-powershell -File tools\internal_ci\helper_scripts\install_python38.ps1
-
 @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 Install Python 3.8.0
+powershell -File tools\internal_ci\helper_scripts\install_python38.ps1
+
 @rem Disable some unwanted dotnet options
 set NUGET_XMLDOC_MODE=skip
 set DOTNET_SKIP_FIRST_TIME_EXPERIENCE=true