Add a manual winget release workflow (#14965)

[The winget-releaser action] automatically generates manifests for the
[Winget Community Repository] and submits them.

I suggest adding Dependabot to keep the action up to date. There were
many cases where the action was failing due to an outdated version.

Closes #14795

[The winget-releaser action]:
https://github.com/vedantmgoyal2009/winget-releaser
[Winget Community Repository]: https://github.com/microsoft/winget-pkgs

(cherry picked from commit bee22f3)

winget: use the correct fork-user

(cherry picked from commit e1079d8)

winget.yml: switch to manually using wingetcreate (#15023)

It was brought to my attention that we should be more restrictive in
which tasks we ovver a GitHub token to. Sorry!

With thanks to sitiom for the version parsing and the magic GitHub
action syntax incantation for determining what is a prerelease.

(cherry picked from commit 5a34d92)

.github/workflows/winget.yml

@@ -0,0 +1,24 @@
+name: Publish to Winget
+
+on:
+  release:
+    types: [published]
+
+env:
+  REGEX: 'Microsoft\.WindowsTerminal(?:Preview)?_Win10_([\d.]+)_8wekyb3d8bbwe\.msixbundle$'
+
+jobs:
+  publish:
+    runs-on: windows-latest # Action can only run on Windows
+    steps:
+      - name: Publish Windows Terminal ${{ github.event.release.prerelease && 'Preview' || 'Stable' }}
+        run: |
+          $assets = '${{ toJSON(github.event.release.assets) }}' | ConvertFrom-Json
+          $wingetRelevantAsset = $assets | Where-Object { $_.name -like '*Win10*' } | Select-Object -First 1
+          $regex = [Regex]::New($env:REGEX)
+          $version = $regex.Match($wingetRelevantAsset.name).Groups[1].Value
+
+          $wingetPackage = "Microsoft.WindowsTerminal${{ github.event.release.prerelease && '.Preview' || '' }}"
+
+          & curl.exe -JLO https://aka.ms/wingetcreate/latest
+          & .\wingetcreate.exe update $wingetPackage -s -v $version -u $wingetRelevantAsset.browser_download_url -t "${{ secrets.WINGET_TOKEN }}"