ci(docs): Update workflow to use just instead of make (#500)

why: docs/Makefile was removed in justfile migration
what:
- Add extractions/setup-just@v2 to install just command runner
- Replace make html with just html for documentation builds

Author: tony

.github/workflows/docs.yml

@@ -52,10 +52,14 @@ jobs:
         if: env.PUBLISH == 'true'
         run: uv sync --all-extras --dev
 
+      - name: Install just
+        if: env.PUBLISH == 'true'
+        uses: extractions/setup-just@v2
+
       - name: Build documentation
         if: env.PUBLISH == 'true'
         run: |
-          pushd docs; make SPHINXBUILD='uv run sphinx-build' html; popd
+          cd docs && just html
 
       - name: Configure AWS Credentials
         if: env.PUBLISH == 'true'