Explicitly install sphinx and sphinx-apidoc

Author: mdpiper

.github/workflows/docs.yml

@@ -21,7 +21,7 @@ jobs:
           auto-activate-base: false
 
       - name: Install dependencies
-        run: pip install .[docs]
+        run: pip install sphinx sphinx-apidoc
 
       - name: Build documentation
         run: make docs