ci(weekly-release): check out the dispatched ref so a dry run exercises that branch's script

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

.github/workflows/weekly-release.yml

@@ -40,9 +40,11 @@ jobs:
       actions: read
       checks: read
     steps:
+      # The dispatched ref supplies the tooling (a dry run from a PR branch
+      # exercises that branch's script); the release candidate always comes
+      # from origin/main, which fetch-depth 0 brings along with every branch.
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
-          ref: main
           fetch-depth: 0
 
       - uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2