update CI rolling (#413)

Signed-off-by: Alejandro Hernández Cordero <[email protected]>

.github/workflows/ci-rolling.yaml

@@ -3,9 +3,9 @@ name: gz_ros2_control CI - Rolling
 on:
   workflow_dispatch:
   pull_request:
-    branches: [ master ]
+    branches: [ rolling ]
   push:
-    branches: [ master ]
+    branches: [ rolling ]
   schedule:
     # Run every morning to detect flakiness and broken dependencies
     - cron: '03 5 * * *'