Merge EPUB check into build-doc job

Author: m-aciek

.github/workflows/reusable-docs.yml

@@ -75,6 +75,17 @@ jobs:
           --fail-if-regression \
           --fail-if-improved \
           --fail-if-new-news-nit
+    - name: 'Build EPUB documentation and load EPUB checks to file'
+      continue-on-error: true
+      run: |
+        set -Eeuo pipefail
+        make -C Doc/ PYTHON=../python SPHINXOPTS="--quiet" epub
+        pip install epubcheck
+        epubcheck Doc/build/epub/Python.epub &> Doc/epubcheck.txt
+    - name: 'Check for FATAL errors in EPUB'
+      if: github.event_name == 'pull_request'
+      run: |
+        python Doc/tools/check-epub.py
 
   # Run "doctest" on HEAD as new syntax doesn't exist in the latest stable release
   doctest:
@@ -102,38 +113,3 @@ jobs:
     # Use "xvfb-run" since some doctest tests open GUI windows
     - name: 'Run documentation doctest'
       run: xvfb-run make -C Doc/ PYTHON=../python SPHINXERRORHANDLING="--fail-on-warning" doctest
-
-  epubcheck:
-    name: 'EPUB check'
-    runs-on: ubuntu-latest
-    timeout-minutes: 40
-    steps:
-    - name: 'Check out latest PR branch commit'
-      uses: actions/checkout@v4
-      with:
-        persist-credentials: false
-        ref: >-
-          ${{
-            github.event_name == 'pull_request'
-            && github.event.pull_request.head.sha
-            || ''
-          }}
-    - name: 'Set up Python'
-      uses: actions/setup-python@v5
-      with:
-        python-version: '3'
-        cache: 'pip'
-        cache-dependency-path: 'Doc/requirements.txt'
-    - name: 'Install build dependencies'
-      run: make -C Doc/ venv
-    - name: 'Build and load EPUB checks to file'
-      continue-on-error: true
-      run: |
-        set -Eeuo pipefail
-        make -C Doc/ PYTHON=../python SPHINXOPTS="--quiet" epub
-        pip install epubcheck
-        epubcheck Doc/build/epub/Python.epub &> Doc/epubcheck.txt
-    - name: 'Check for FATAL errors in EPUB'
-      if: github.event_name == 'pull_request'
-      run: |
-        python Doc/tools/check-epub.py