Add WinGet release workflow

[Aragas]

Adds winget-release.yml, which submits new stable releases of NexusMods.Vortex to microsoft/winget-pkgs via winget-releaser, pushing the manifest branch to the Nexus-Mods/winget-pkgs fork.

• Fires on release: released (stable only; pre-releases never trigger it, plus a guard against tags containing -)
• workflow_dispatch with a tag input for backfills / re-runs
• Installer regex anchored to vortex-setup-X.Y.Z.exe so .blockmap / latest.yml can't match
• Uses WINGET_GITHUB_PAT (classic PAT with Write on the fork); GITHUB_TOKEN / App tokens can't open PRs on microsoft/winget-pkgs

First real run after merge: gh workflow run winget-release.yml -f tag=v2.6.2, which backfills 2.6.2 (winget-pkgs is currently at 2.6.1).

We can't set the icon atm, we'll need the Verified Developer status first

The WinGet community repository has a set of policies restricting the use of certain manifest fields in PRs. These policies primarily affect optional metadata fields restricted to verified developers. Some fields are automatically populated during our validation process like the fields for icons.

Note: The verified developer workflow is still in progress.

The end result PR

[github-actions]

This PR has been marked as stale due to inactivity.

[Aragas]

Content Team confirmed in CON-585 that the text is fine

[github-actions]

This PR has been marked as stale due to inactivity.