docs: Use requirements_dev.txt

.readthedocs.yaml

@@ -26,7 +26,7 @@ formats: all
 # Optionally declare the Python requirements required to build your docs
 python:
   install:
-    - requirements: requirements.txt
+    - requirements: requirements_dev.txt
 
 # You can include or exclude git submodules from the Read the Docs
 # documentation build.