Revert LaTeX tests use Docutils HEAD from PR sphinx-doc#13657

This was done to force using 0.22, but this is now the latest release of
Docutils, so the added LaTeX build tests for CSS3 length units will be
executed.

Author: jfbu

.github/workflows/main.yml

@@ -312,8 +312,6 @@ jobs:
         enable-cache: false
     - name: Install dependencies
       run: uv pip install . --group test
-    - name: Install Docutils' HEAD
-      run: uv pip install "docutils @ git+https://repo.or.cz/docutils.git#subdirectory=docutils"
     - name: Test with pytest
       run: python -m pytest -vv --durations 25
       env: