Unblock doc CI (#697)

Pin to run on ubuntu 22.04 since docc CI doesn't support python 3.12 in
ubuntu 24.04.

Signed-off-by: Lianhao Lu <lianhao.lu@intel.com>

Author: lianhao

.github/workflows/check-online-doc-build.yml

@@ -13,7 +13,7 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     steps:
 
     - name: Checkout