run posix workflow

Author: mattip

.github/workflows/posix.yml

@@ -4,7 +4,9 @@ on:
   push:
     branches: [ main ]
   pull_request:
-    branches: [ main ]
+    branches:
+      - main
+      - maintenance/**
   workflow_dispatch: null
   schedule:
     - cron: '0 0 * * 0'