ci: make step conditions more structured

Either have a step always be executed, be executed for prod or be
executed for a PR (staging) and use the same conditions for each of
these cases.

.forgejo/workflows/deploy.yaml

@@ -10,20 +10,15 @@ env:
   TZ: Europe/Berlin
 
 jobs:
-  pipeline-info:
-    runs-on: docker
-    container:
-      image: code.forgejo.org/oci/node:22-bookworm
-    steps:
-      - name: Pipeline info
-        run: |
-          echo "Run triggered by ${{ github.event_name }} (${{ github.event.action }}) on ref ${{ github.ref_name }}"
-
   build:
     runs-on: docker
     container:
       image: hugomods/hugo:exts-0.148.1
     steps:
+      - name: Pipeline info
+        run: |
+          echo "Run triggered by ${{ github.event_name }} (${{ github.event.action }}) on ref ${{ github.ref_name }}"
+
       - name: Install packages
         run: |
           apk update