chore(ci): merge CNB and AtomGit mirror sync into single workflow

.github/workflows/sync-mirrors.yml

@@ -0,0 +1,47 @@
+name: Sync Mirrors
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - "**"
+  delete:
+  workflow_dispatch:
+
+jobs:
+  sync-cnb:
+    name: Sync to CNB
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Push to CNB
+        env:
+          CNB_TOKEN: ${{ secrets.CNB_TOKEN }}
+        run: |
+          set -euo pipefail
+          git remote add cnb "https://cnb:${CNB_TOKEN}@cnb.cool/dbxio.com/dbx.git"
+          git push cnb --all --force
+          git push cnb --tags --force
+
+  sync-atomgit:
+    name: Sync to AtomGit
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Push to AtomGit
+        env:
+          ATOMGIT_TOKEN: ${{ secrets.ATOMGIT_TOKEN }}
+        run: |
+          set -euo pipefail
+          git remote add atomgit "https://t8y2:${ATOMGIT_TOKEN}@atomgit.com/t8y2/dbx.git"
+          git push atomgit --all --force
+          git push atomgit --tags --force