Fix sync workflow credentials

Author: ethanj

.github/workflows/sync-to-private.yml

@@ -13,18 +13,18 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Push to Private Repo
         env:
           SYNC_TOKEN: ${{ secrets.SYNC_TOKEN }}
-          SYNC_USER: ${{ github.actor }}
         run: |
           # Configure Git identities
           git config --global user.name "GitHub Action Bot"
           git config --global user.email "actions@github.com"
 
           # Add the atomicmemory-internal repository as a secure remote
-          git remote add private-target "https://${SYNC_USER}:${SYNC_TOKEN}@github.com/atomicstrata/atomicmemory-internal.git"
+          git remote add private-target "https://x-access-token:${SYNC_TOKEN}@github.com/atomicstrata/atomicmemory-internal.git"
 
           # Force push the main branch to the private repo to ensure perfect alignment
           git push private-target HEAD:main --force