ci: rework review_docs job

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/2286>

.gitlab-ci.yml

@@ -73,41 +73,36 @@ review_front:
 
 review_docs:
   interruptible: true
-  stage: review
   allow_failure: true
-  image: python:3.11
+  stage: review
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
+      changes: [docs/**/*]
+
+  image: $CI_REGISTRY/funkwhale/ci/python:3.11
   variables:
     BUILD_PATH: "../docs-review"
+  environment:
+    name: review/docs/$CI_COMMIT_REF_NAME
+    url: http://$CI_PROJECT_NAMESPACE.pages.funkwhale.audio/-/$CI_PROJECT_NAME/-/jobs/$CI_JOB_ID/artifacts/docs-review/index.html
+  cache:
+    key: "$CI_PROJECT_ID__sphinx"
+    paths: [$PIP_CACHE_DIR]
   before_script:
-    - rm -rf docs-review
     - mkdir docs-review
     - cd docs
     - apt-get update
     - apt-get install -y graphviz git
-    - pip install poetry
     - poetry install
     - git switch develop && git pull
     - git switch stable && git pull
     - git switch $CI_COMMIT_BRANCH && git pull
   script:
     - poetry run python3 -m sphinx . $BUILD_PATH
-  cache:
-    key: "$CI_PROJECT_ID__sphinx"
-    paths:
-      - "$PIP_CACHE_DIR"
   artifacts:
     expire_in: 2 weeks
     paths:
       - docs-review
-  environment:
-    name: review/docs/$CI_COMMIT_REF_NAME
-    url: http://$CI_PROJECT_NAMESPACE.pages.funkwhale.audio/-/$CI_PROJECT_NAME/-/jobs/$CI_JOB_ID/artifacts/docs-review/index.html
-  rules:
-    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
-      changes:
-        - docs/**/*
-    - if: $CI_PIPELINE_SOURCE != "merge_request_event" && $CI_COMMIT_REF_NAME != $CI_DEFAULT_BRANCH
-      when: manual
 
 find_broken_links:
   extends: [.lychee]