action: adds gitlab ssh-key usage to workflow

Author: mosmuell

.github/workflows/release.yml

@@ -56,6 +56,13 @@ jobs:
           irm https://astral.sh/uv/install.ps1 | iex
           echo "$env:USERPROFILE\.local\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
 
+      - name: Configure SSH for GitLab
+        run: |
+          mkdir -p ~/.ssh
+          echo "${{ secrets.GITLAB_SSH_KEY }}" > ~/.ssh/id_ed25519
+          chmod 600 ~/.ssh/id_ed25519
+          ssh-keyscan gitlab.phys.ethz.ch >> ~/.ssh/known_hosts
+
       - name: Sync build dependencies
         run: uv sync --group build