Description:
It should be possible to have setup-dotnet download and install the .NET SDKs from:

• https://aka.ms/dotnet/6.0/daily/
• https://aka.ms/dotnet/6.0/preview/

Each of them also contain a text file for each platform and CPU bitness that the installers are available in and it contains the versions of those installers:

• productCommit-win-x64.txt for 64 bit Windows.
• productCommit-linux-x64.txt for 64 bit linux.
• productCommit-osx-x64.txt for 64 bit MacOS.

The installer files (SDKs and not the runtimes):

• dotnet-sdk-win-x64.exe
• dotnet-sdk-linux-x64.tar.gz
• dotnet-sdk-osx-x64.pkg

Justification:
I need this and the ability to tell the action use the preview feed which is the one this action currently uses or the use the daily feed which is the feed that contains the Preview 7 versions, the rc.1 versions of .NET 6, etc which my codebase needs that Preview 6 lacks.

Are you willing to submit a PR?

If the change is not too hard to make that is.