ci(docs): update Sphinx workflow to use sphinx-notes/pages action

Replaced `uncch-rdmc/sphinx-action` with `sphinx-notes/pages` for better compatibility and flexibility (Python & Sphinx versions!!!). Added dynamic Sphinx version lookup and updated paths and options to align with the new action requirements.

Author: poikilotherm

.github/workflows/guides_build_sphinx.yml

@@ -11,6 +11,15 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - uses: uncch-rdmc/sphinx-action@master
+    - id: lookup
+      run: |
+        echo "sphinx_version=$(grep Sphinx== ./doc/sphinx-guides/requirements.txt | tr -s "=" | cut -f 2 -d=)" | tee -a "${GITHUB_OUTPUT}"
+    - uses: sphinx-notes/pages@v3
       with:
-        docs-folder: "doc/sphinx-guides/"
+        documentation_path: ./doc/sphinx-guides/source
+        requirements_path: ./doc/sphinx-guides/requirements.txt
+        sphinx_version: ${{ steps.lookup.outputs.sphinx_version }}
+        sphinx_build_options: "-W"
+        cache: false
+        publish: false
+