update stable if push to master is successful

.gitea/workflows/commit.yaml

@@ -37,3 +37,24 @@ jobs:
           echo "$ANSIBLE_VAULT_PASSWORD" > .vault_pass.txt
           ansible-playbook --vault-password-file .vault_pass.txt deploy-to-prod.yaml
           rm .vault_pass.txt
+
+  promote_stable:
+    runs-on: debian-latest
+    needs: deploy
+    steps:
+      - name: Promote master to stable
+        env:
+          SPEEDBB_REPO: ${{ vars.SPEEDBB_REPO }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          GITEA_ACTOR: ${{ gitea.actor }}
+        run: |
+          set -e
+          REPO="$SPEEDBB_REPO"
+          if [ -n "$GITEA_TOKEN" ]; then
+            REPO=$(echo "$SPEEDBB_REPO" | sed "s#https://#https://${GITEA_ACTOR}:${GITEA_TOKEN}@#")
+          fi
+          git clone --quiet --depth=1 --branch=stable "$REPO" repo
+          cd repo
+          git fetch origin master
+          git merge --ff-only origin/master
+          git push origin stable