Revert "Refactor Woodpecker pipeline: consolidate when conditions, replace secrets with environment for Fly.io auth."

This reverts commit 4f8feb8652.

.woodpecker.yml

@@ -1,27 +1,23 @@
 steps:
   deploy_frontend:
     image: node:20
-    environment:
-      FLY_API_TOKEN:
-        from_secret: FLY_API_TOKEN
+    secrets: [FLY_API_TOKEN]
     commands:
       - curl -L https://fly.io/install.sh | sh
       - export PATH="$HOME/.fly/bin:$PATH"
       - flyctl deploy --config fly.toml --app gallus-pub --remote-only
+    when:
+      branch: main
+      event: push
 
-  build_and_deploy_backend:
+  deploy_backend:
     image: node:20
-    environment:
-      FLY_API_TOKEN:
-        from_secret: FLY_API_TOKEN
+    secrets: [FLY_API_TOKEN]
     commands:
       - cd backend
       - curl -L https://fly.io/install.sh | sh
       - export PATH="$HOME/.fly/bin:$PATH"
       - flyctl deploy --config fly.toml --app gallus-cms-backend --remote-only
-
     when:
-  branch:
-    - main
-  event:
-    - push
+      branch: main
+      event: push