trigger the workflow when updating it

.github/workflows/update_examples.yml

@@ -4,10 +4,12 @@ on:
   workflow_dispatch:
   push:
     paths:
+      - '.gitbub/workflows/update_examples.yml'
       - 'examples/**'
       - 'tools/rexm/**'
   pull_request:
     paths:
+      - '.gitbub/workflows/update_examples.yml'
       - 'examples/**'
       - 'tools/rexm/**'