add a deploy key

Change-Id: I581a8f43544b09e8dfdd3b08cec7c71371b3ee5d

.github/workflows/sync-to-gerrit.yaml

diff --git a/.github/workflows/sync-to-gerrit.yaml b/.github/workflows/sync-to-gerrit.yaml
index 518a9c7..ee64d7c 100644
--- a/.github/workflows/sync-to-gerrit.yaml
+++ b/.github/workflows/sync-to-gerrit.yaml
@@ -15,6 +15,7 @@
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
+          ssh-key: ${{ secrets.DEPLOY_KEY }}
 
       - name: Pull from Gerrit and Push to GitHub
         env:
@@ -24,4 +25,4 @@
           git fetch gerrit --prune --tags
 
           git push origin "+refs/remotes/gerrit/*:refs/heads/*"
-          git push origin --tags --force
\ No newline at end of file
+          git push origin --tags --force