release: notes list calls as a known issue, and new releases start as pre-releases

.github/workflows/release.yml

@@ -48,3 +48,6 @@ jobs:
           # The hand-written notes go first; GitHub adds the full changelog link under them.
           body_path: .github/release-notes.md
           generate_release_notes: true
+          # Every release starts as a pre-release: only phones on the Alpha update channel get it.
+          # Once it's tested, untick pre-release on GitHub and everyone gets it.
+          prerelease: true