[backport] Fix read the doc configuration. [skip ci] (dmlc#9549)

trivialfis · web-flow · commit 177fd7986400 · 2023-09-05T17:32:00.000+08:00
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
@@ -32,4 +32,3 @@ formats:
 python:
   install:
    - requirements: doc/requirements.txt
-  system_packages: true
