Update pages.yml folder filter and platform

.github/workflows/pages.yml

@@ -3,13 +3,16 @@ name: Build html using Sphinx and upload to Github-pages
 on:
   push:
     branches: [ "main" ]
+    paths:
+      - "pysyncon/**"
+      - "doc/**"
 
 permissions:
   contents: read
 
 jobs:
   pages:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     environment:
       name: github-pages
       url: ${{ steps.deployment.outputs.page_url }}