Switched to PDM for package management

.github/workflows/apidocs.yml

@@ -29,8 +29,10 @@ jobs:
       - uses: actions/setup-python@v4
         with:
           python-version: "3.9"
-      - run: pip install -e .
-      - run: spoolman_docs
+      - run: pip install pip setuptools wheel
+      - run: pip install pdm
+      - run: pdm sync
+      - run: pdm run docs
       - name: Setup Pages
         uses: actions/configure-pages@v3
       - name: Upload artifact