[fix] Modify .yaml configuration to have build.os entry (#3120)

.readthedocs.yaml

@@ -8,7 +8,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.7"
+    python: 3.7
 
 # Build documentation in the docs/ directory with Sphinx
 # reference: https://docs.readthedocs.io/en/stable/config-file/v2.html#sphinx
@@ -22,7 +22,6 @@ formats:
 
 # Optionally set the version of Python and requirements required to build your docs
 python:
-  version: 3.7
   install:
     - requirements: requirements.dev.txt
     - requirements: docs/requirements.txt