deploy: switch HARBOR env vars to REGISTRY

.gitea/workflows/deploy.yml

@@ -7,6 +7,8 @@ on:
 jobs:
   deploy:
     runs-on: nixos
+    env:
+      NIX_CONFIG: "experimental-features = nix-command flakes"
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4

flake.nix

@@ -23,10 +23,10 @@
 
           # 2. Authenticate if CI environment variables are present
           if [ -n "''${REGISTRY_USERNAME:-}" ] && [ -n "''${REGISTRY_PASSWORD:-}" ]; then
-            echo "CI Environment detected: Logging in to Harbor."
+            echo "CI Environment detected: Logging in to registry."
             ${pkgs.skopeo}/bin/skopeo login gitlab.julian-mutter.de \
-              --username "''${HARBOR_USERNAME}" \
-              --password "''${HARBOR_PASSWORD}"
+              --username "''${REGISTRY_USERNAME}" \
+              --password "''${REGISTRY_PASSWORD}"
           else
             echo "Local Environment detected: Skipping login, relying on existing auth."
           fi