[ENG-3584] WinGet: ReleaseNotesUrl only; drop embedded changelog (#4584)

## Summary

- Stop embedding GoReleaser changelog in winget locale manifests
(`release_notes: "{{.Changelog}}"`), which triggered WinGet YAML / IEDS
issues on
[microsoft/winget-pkgs#353821](microsoft/winget-pkgs#353821).
- Add `release_notes_url` pointing at public GitHub releases on
`overmindtech/cli` (`{{ .Tag }}`), so manifests carry
**ReleaseNotesUrl** only and omit **ReleaseNotes** (GoReleaser
`omitempty`).

## Linear Ticket

- **Ticket**:
[ENG-3584](https://linear.app/overmind/issue/ENG-3584/unblock-winget-pkgs-pr-overmindcli-1173-manifest-validation-ieds)
— Unblock winget-pkgs PR: OvermindCLI 1.17.3 manifest validation (IEDS /
ReleaseNotes YAML)
- **Purpose**: Fix winget manifest generation so Microsoft validation
can succeed; follow up with a **new** CLI release and fresh winget-pkgs
PR (abandon stuck 1.17.3 PR per plan).

## Changes

- [`cli/.goreleaser.yaml`](cli/.goreleaser.yaml): remove
`release_notes`; add `release_notes_url:
"https://github.com/overmindtech/cli/releases/tag/{{ .Tag }}"`.

## Approved Plan

- **Plan approver**: James Lane
- **Linear ticket**:
[ENG-3584](https://linear.app/overmind/issue/ENG-3584/unblock-winget-pkgs-pr-overmindcli-1173-manifest-validation-ieds)
(implementation plan appended in ticket description)

> Deviation analysis and reviewer assignment are handled automatically
by the
> pre-approved PR review automation (see docs/PREAPPROVED_CHANGES.md).

## Deviations from Approved Plan

> Implementation matches the approved plan — no material deviations.

Made with [Cursor](https://cursor.com)

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: only adjusts GoReleaser WinGet manifest metadata, affecting
release note linking but not build artifacts or runtime code.
>
> **Overview**
> Updates the WinGet packaging config in `cli/.goreleaser.yaml` to
**stop embedding generated changelog text** in manifests and instead
publish only a `release_notes_url` pointing to the matching GitHub
release tag (`https://github.com/overmindtech/cli/releases/tag/{{ .Tag
}}`). This changes WinGet output to reference release notes externally
rather than inlining them.
>
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
0456efb0e875b063aac6f3d94a2f46a0dd4b8036. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

GitOrigin-RevId: 81205189238f96e19ee6c83b8aee9e89df65af99

Author: dylanratcliffe

.goreleaser.yaml

@@ -104,13 +104,7 @@ winget:
     # in case there is an indicator for prerelease in the tag e.g. v1.0.0-rc1
     skip_upload: auto
 
-    # Release notes.
-    #
-    # If you want to use the release notes generated by GoReleaser, use
-    # `{{.Changelog}}` as the value.
-    #
-    # Templates: allowed
-    release_notes: "{{.Changelog}}"
+    release_notes_url: "https://github.com/overmindtech/cli/releases/tag/{{ .Tag }}"
 
     # Repository to push the generated files to.
     repository: