chore: change ubuntu pinned version to ubuntu-lts-latest (#178)

Ticket: https://2u-internal.atlassian.net/browse/BOMS-210

Author: edx-requirements-bot

.readthedocs.yaml

@@ -6,7 +6,7 @@
 version: 2
 
 build:
-  os: "ubuntu-22.04"
+  os: "ubuntu-lts-latest"
   tools:
     python: "3.8"