update .readthedocs.yml

Author: dhalbert

.readthedocs.yml

@@ -14,7 +14,7 @@ build:
         python: "3"
     jobs:
         post_install:
-            - python tools/ci_fetch_deps.py docs HEAD
+            - python tools/ci_fetch_deps.py build-doc
 
 formats:
     - pdf