Provis. ignore onerror depr. warn when install. DocUtils with 3.12-dev

Author: jfbu

.github/workflows/main.yml

@@ -58,6 +58,12 @@ jobs:
         PYTHONWARNINGS: ""
     - name: Install Docutils ${{ matrix.docutils }}
       run: python -m pip install --upgrade "docutils==${{ matrix.docutils }}.*"
+      if: "!endsWith(matrix.python, '-dev')"
+    - name: Install Docutils ${{ matrix.docutils }} (ignore warnings)
+      run: python -m pip install --upgrade "docutils==${{ matrix.docutils }}.*"
+      if: "endsWith(matrix.python, '-dev')"
+      env:
+        PYTHONWARNINGS: ""
     - name: Test with pytest
       run: python -m pytest -vv --durations 25