fix docs python version incompatibility (sunlabuiuc#521)

Co-authored-by: John Wu <johnwu3@sunlab-serv-03.cs.illinois.edu>

This change is so small and silly, it shouldn't require a review from a maintainer.

Author: jhnwu3

docs/.readthedocs.yaml

@@ -3,7 +3,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.8"
+    python: "3.10"
 
 sphinx:
     configuration: docs/conf.py