Support stable branch releases

- release.yml: Trigger on *-stable branches
- post-release.yml: Pass target_branch from workflow_run event

Author: tvdeyen

.github/workflows/post-release.yml

@@ -12,6 +12,7 @@ jobs:
     uses: AlchemyCMS/.github/.github/workflows/post-release.yml@main
     with:
       version_file_path: lib/alchemy/version.rb
+      target_branch: ${{ github.event.workflow_run.head_branch }}
     secrets:
       app_id: ${{ vars.ALCHEMY_BOT_APP_ID }}
       app_private_key: ${{ secrets.ALCHEMY_BOT_APP_PRIVATE_KEY }}

.github/workflows/release.yml

@@ -6,6 +6,7 @@ on:
     types: [closed]
     branches:
       - main
+      - '*-stable'
 
 jobs:
   publish: