.NET Core runtime is always downloaded automatically no matter if it is installed already

[byyxx128]

Up to 0.13.2, when I run the EXE installer of PowerToys, I always see a window saying "downloading .NET runtime", then the installer of .NET runtime appears for a few seconds before I can see the main window of PowerToys installer. That is because I have .NET runtime installed already before I install PowerToys.

I think we can have the following solutions:

1. Check if the runtime is installed and check if it is up-to-date if necessary before the installer of PowerToys running. But do NOT download the runtime automatically with no prompt.
2. Give an option to allow users to choose whether downloading the .NET runtime directly through the installer of PowerToys.
   
3. Based on 1&2, we can also do this: if the latest runtime is not installed, the installer can be like this.
   
4. The runtime can be updated automatically if necessary while the PowerToys updating itself. However, an option or prompt is necessary as well.

All in all, the runtime should not be downloaded automatically without any prompt.

[enricogior]

@byyxx128
the bootstrapper checks the current installed version of .NET Core and it it's equal or greater of the required version by PT it will install it.
We are not going to change this behavior since it's the only way to guarantee the PT will work as expected.

[byyxx128]

@enricogior Not so. As I said, even though I have the latest .NET Core runtime installed already, I can still see the dialog box saying "downloading .NET runtime", and the windows of the installer of .NET Core will only appear for a few seconds, then shows the PT installer.

What I mean is, if I do not have .NET Core runtime installed or the version is lower than necessary, it is okay to be installed by the PT installer. However, PT installer always downloads and installs .NET Core runtime no matter if I did. It will not check if I have. That is the problem.