ci: fix missing SSH known_hosts in deploy pipeline

.drone.yml

@@ -27,9 +27,11 @@ steps:
       NIX_FLAGS: "--print-build-logs --verbose --accept-flake-config"
       PRIVATE_SSH_KEY:
         from_secret: ci_private_ssh_key
+      SSH_HOST_KEY: "80.244.242.4 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIE7XTCHfX6ta8EtkdOcZLnpdhMmXDfTebVMs4NC8JEPj"
     commands:
       - "mkdir ~/.ssh && chmod 700 ~/.ssh"
       - echo "$$PRIVATE_SSH_KEY" > ~/.ssh/id_ed25519 && chmod 600 ~/.ssh/id_ed25519
+      - echo "$$SSH_HOST_KEY" > ~/.ssh/known_hosts
       - 'echo DEBUG: Using NIX_FLAGS: $NIX_FLAGS'
       - nix $$NIX_FLAGS develop --command deploy --magic-rollback false --skip-checks --targets '.#host_001_momo_koeln'
 
@@ -157,6 +159,6 @@ volumes:
 
 ---
 kind: signature
-hmac: e50c1347f8645fa2591afa05643eb0c293b70ef1628d157d16d3d819b27f6e7c
+hmac: 25f44352119a730c7095de249676f5857589865bd1f676fa050f3e3499b74387
 
 ...