Ensure poetry env is activated when building docs

Author: u8sand

.github/workflows/deploy-doc-to-ghpages.yml

@@ -18,7 +18,7 @@ jobs:
         pip install llvmlite poetry
         poetry install -E docs
     - name: Building docs
-      run: cd docs && make build-html
+      run: eval $(poetry env activate) && cd docs && make build-html
     - name: Deploy
       uses: peaceiris/actions-gh-pages@v3
       with: