update ssh key

Author: marcoieni

.github/workflows/example-sync.yaml

@@ -30,7 +30,7 @@ jobs:
 with:
 repository: rust-github/rust-gh-example
 path: old_example
-ssh-key: ${{secrets.GITHUB_TOKEN }}
+ssh-key: ${{secrets.GH_EXAMPLE_DEPLOY_SECRET }}
 
  - name: move sources from old to new example
 run: |