ci: reuse build target when deploying pages

.gitlab-ci.yml

+---
+default:
+  image: "archlinux:latest"
+
 variables:
   GIT_SUBMODULE_STRATEGY: recursive
 
+stages:
+  - build
+  - deploy
+
 .hugo:
   script:
     - pacman -Syu --needed --noconfirm hugo git
     - hugo
+
+build:
+  stage: build
+  needs: []
+  script:
+    - pacman -Syu --needed --noconfirm hugo git
+    - hugo
   artifacts:
     paths:
       - public
 
-test:
-  extends: .hugo
-  stage: test
-  rules:
-    - if: $CI_PROJECT_PATH != "archlinux/monthly-reports" || $CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH
-
 pages:
-  extends: .hugo
   stage: deploy
+  needs:
+    - build
   tags:
     - secure
+  script:
+    - "true"
+  artifacts:
+    paths:
+      - public
   rules:
     - if: $CI_PROJECT_PATH == "archlinux/monthly-reports" && $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH