Add Winget automation to GoReleaser

[tashian]

This is blocked on goreleaser/goreleaser#4196

To test the Winget package itself:

• Create a prerelease on this branch
• Look in the dist folder in the workflow artifacts, for the Winget manifest files
• Compare them to my hand-crafted winget yaml files for step, make sure all the critical fields are present and populated properly
• Create a PR on microsoft/winget-pkgs using the yaml files, and see if it passes validations

To test the Winget PR automation:

• Create a smallstep/winget-pkgs repo that is a fork of microsoft/winget-pkgs.
• In .goreleaser.yml, set skip_upload: false and then push a pre-release
• Make sure the generated YAML looks great.
• See if a PR is created properly in smallstep/winget-pkgs.

Before merging this:

• Configure .goreleaser.yml to use microsoft/winget-pkgs as the base package (uncomment lines 351-354)
• Change skip_upload to auto, so that prereleases no longer trigger PRs

[tashian]

this is unblocked.

[tashian]

I think the only thing this needs now is for the GH action token to have permission to create a PR on microsoft/winget-pkgs once everything is done. See this error in the action run:

   • winget.pull_request enabled, creating a PR
      • error checking for default branch            projectID= statusCode=404 error=GET https://api.github.com/repos//: 404 Not Found []

EDIT: This turned out to be a GoReleaser bug, which is now fixed and is in the GoReleaser 1.21 milestone (not yet released).

[tashian]

GoReleaser 1.21 is out, so this is ready for merge