fix(docs): run sphinx-build inside poetry venv (#178)

Install docs dependencies and run sphinx-build through poetry run
so that project packages (orjson, etc.) are available to conf.py.

Author: bsbodden

.github/workflows/docs.yml

@@ -44,7 +44,7 @@ jobs:
         run: poetry install --all-extras
 
       - name: Install docs dependencies
-        run: pip install -r docs/requirements.txt
+        run: poetry run pip install -r docs/requirements.txt
 
       - name: Build versioned documentation
         run: |
@@ -72,8 +72,8 @@ jobs:
             fi
 
             git checkout "$tag" -- docs/ examples/ || git checkout "$tag" -- docs/
-            python docs/copy_notebooks.py || true
-            sphinx-build -b html docs "$OUTPUT_DIR/$tag"
+            poetry run python docs/copy_notebooks.py || true
+            poetry run sphinx-build -b html docs "$OUTPUT_DIR/$tag"
             git checkout HEAD -- docs/ examples/ 2>/dev/null || git checkout HEAD -- docs/
 
             if [ -z "$LATEST_TAG" ]; then
@@ -89,8 +89,8 @@ jobs:
           # Build docs for main (current HEAD)
           echo "=== Building docs for main ==="
           git checkout HEAD -- docs/ examples/ 2>/dev/null || true
-          python docs/copy_notebooks.py
-          sphinx-build -b html docs "$OUTPUT_DIR/main"
+          poetry run python docs/copy_notebooks.py
+          poetry run sphinx-build -b html docs "$OUTPUT_DIR/main"
 
           VERSIONS_JSON=$(echo "$VERSIONS_JSON" | python3 -c "
           import json, sys