Run integration workflow on version branches (#210)

Author: uglide

.github/workflows/integration.yaml

@@ -8,11 +8,11 @@ on:
       - '**/*.md'
     branches:
       - master
-      - '[0-9].[0-9]'
+      - 'v[0-9].[0-9]'
   pull_request:
     branches:
       - master
-      - '[0-9].[0-9]'
+      - 'v[0-9].[0-9]'
 
 permissions:
   contents: read  #  to fetch code (actions/checkout)