ci(release): automate signed release tags and release notes (#39544) (#39622)

Backport #39544

Co-authored-by: bircni <bircni@icloud.com>
Co-authored-by: bircni <bircni@users.noreply.github.com>
Co-authored-by: silverwind <me@silverwind.io>

contrib/upgrade.sh

@@ -87,7 +87,7 @@ echo "Checking currently installed version..."
 current=$(giteacmd --version | cut -d ' ' -f 3)
 [[ "$current" == "$giteaversion" ]] && echo "$current is already installed, stopping." && exit 0
 if [[ -z "${no_confirm:-}"  ]]; then
-  echo "Make sure to read the changelog first: https://github.com/go-gitea/gitea/blob/main/CHANGELOG.md"
+  echo "Make sure to read the changelog first: https://github.com/go-gitea/gitea/releases"
   echo "Are you ready to update Gitea from ${current} to ${giteaversion}? (y/N)"
   read -r confirm
   [[ "$confirm" == "y" ]] || [[ "$confirm" == "Y" ]] || exit 1