add darwin deploy action

.github/workflows/darwin.yml

@@ -0,0 +1,50 @@
+name: "darwin"
+
+on:
+  push:
+    branches: [master]
+  workflow_dispatch:
+
+concurrency:
+  group: "darwin"
+  cancel-in-progress: false
+
+jobs:
+  deploy:
+    environment:
+      name: darwin
+    strategy:
+      fail-fast: false
+      matrix:
+        host: [darwin02, darwin03]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install Nix
+        uses: cachix/install-nix-action@v23
+        with:
+          extra_nix_config: |
+            accept-flake-config = true
+            experimental-features = nix-command flakes
+      - name: Setup SSH
+        env:
+          SSH_KEY: "${{ secrets.SSH_KEY }}"
+        run: |
+          mkdir -p "$HOME/.ssh"
+          cat >>"$HOME/.ssh/id_ed25519" <<EOF
+          $SSH_KEY
+          EOF
+          chmod 600 "$HOME/.ssh/id_ed25519"
+          cat >>"$HOME/.ssh/known_hosts" <<EOF
+          darwin02.nix-community.org ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICJqwpMUEl1/iwrBakeDb1rlheXlE5mfDLICVz8w6yi6
+          darwin03.nix-community.org ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKX7W1ztzAtVXT+NBMITU+JLXcIE5HTEOd7Q3fQNu80S
+          EOF
+          cat >>"$HOME/.ssh/config" <<EOF
+          Host *
+            IdentityFile ~/.ssh/id_ed25519
+            IdentitiesOnly yes
+            User hetzner
+          EOF
+      - name: Deploy
+        run: |
+          ./inv deploy --hosts ${{ matrix.host }}