Refactor .woodpecker.yml pipeline configuration

- Renamed pipeline to "deploy" for clarity.
- Adjusted `when` conditions structure for branch and event targeting.

.woodpecker.yml

@@ -1,11 +1,15 @@
-pipeline:
+name: deploy
+
+steps:
   deploy:
     image: node:20
     commands:
       - curl -L https://fly.io/install.sh | sh
       - export PATH="$HOME/.fly/bin:$PATH"
       - flyctl deploy --config fly.toml --app gallus-pub
-    when:
-      event: push
-      branch:
-        - main
+
+when:
+  branch:
+    - main
+  event:
+    - push