Revert "Tmp remove ssh key"

This reverts commit 7c0d583.

Author: nomeata

.github/workflows/update-stage0.yml

@@ -24,6 +24,8 @@ jobs:
     # uses a deploy key with write permissions, as suggested at
     # https://stackoverflow.com/a/76135647/946226
     - uses: actions/checkout@v4
+      with:
+        ssh-key: ${{secrets.STAGE0_SSH_KEY}}
     - run: echo "should_update_stage0=yes" >> "$GITHUB_ENV"
     - name: Check if automatic update is needed
       if: github.event_name == 'push'