ci(actions): Update extractions/setup-just v2 to v3

why: Keep CI dependencies current
what:
- Update extractions/setup-just from v2 to v3

refs:
- https://github.com/extractions/setup-just/releases/tag/v3.0.0

Author: tony

.github/workflows/docs.yml

@@ -51,7 +51,7 @@ jobs:
         run: uv sync --all-extras --dev
 
       - name: Install just
-        uses: extractions/setup-just@v2
+        uses: extractions/setup-just@v3
 
       - name: Print python versions
         if: env.PUBLISH == 'true'