ci: Introduce sphinx as a "must-be-green" job

Author: thomass-dev

.github/workflows/sphinx.yml

@@ -48,21 +48,9 @@ name: sphinx
 
 on:
   pull_request:
-    paths:
-      - '.github/actions/sphinx/**'
-      - '.github/workflows/sphinx.yml'
-      - 'examples/**'
-      - 'sphinx/**'
-      - 'skore/**'
   push:
     branches:
       - main
-    paths:
-      - '.github/actions/sphinx/**'
-      - '.github/workflows/sphinx.yml'
-      - 'examples/**'
-      - 'sphinx/**'
-      - 'skore/**'
   release:
     types: [released]
   merge_group:
@@ -73,8 +61,32 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  sphinx-changes:
+    runs-on: ubuntu-latest
+    outputs:
+      changes: ${{ steps.filter.outputs.sphinx }}
+    permissions:
+      pull-requests: read
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+
+      - name: Define if at least one file has changed
+        uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36 # v3.0.2
+        id: filter
+        with:
+          filters: |
+            sphinx:
+              - '.github/actions/sphinx/**'
+              - '.github/workflows/sphinx.yml'
+              - 'examples/**'
+              - 'sphinx/**'
+              - 'skore/**'
+
   sphinx-version:
     runs-on: ubuntu-latest
+    needs: [sphinx-changes]
+    if: ${{ (! contains(fromJSON('["pull_request", "merge_group"]'), github.event_name)) || needs.backend-changes.outputs.changes == 'true' }}
     outputs:
       SPHINX_VERSION: ${{ steps.sphinx-version.outputs.SPHINX_VERSION }}
       SPHINX_RELEASE: ${{ steps.sphinx-version.outputs.SPHINX_RELEASE }}
@@ -99,7 +111,8 @@ jobs:
 
   sphinx-build:
     runs-on: ubuntu-latest
-    needs: sphinx-version
+    needs: [sphinx-version]
+    if: ${{ (! contains(fromJSON('["pull_request", "merge_group"]'), github.event_name)) || needs.backend-changes.outputs.changes == 'true' }}
     steps:
       - uses: actions/checkout@v4
         with:
@@ -241,3 +254,18 @@ jobs:
       - uses: geekyeggo/delete-artifact@v5
         with:
           name: sphinx-html-artifact
+
+  sphinx:
+    needs:
+      - sphinx-changes
+      - sphinx-version
+      - sphinx-build
+      - sphinx-deploy-html
+      - sphinx-deploy-root-files
+      - sphinx-clean-artifacts
+    if: ${{ always() }}
+    runs-on: Ubuntu-latest
+    steps:
+      - shell: bash
+        run: |
+          [[  ${{ contains(needs.*.result, 'failure') }} = false ]]