workflow changes (#138)

Co-authored-by: SHENGXING LU <slu@SHENGXINGs-MacBook-Air.local>

Author: sluFicodes

.github/workflows/system-testing.yml

@@ -5,7 +5,6 @@ on:
     types: [opened, reopened, synchronize]
     branches:
       - main
-      - slu/e2eExternal
 
 jobs:
   trigger-system-tests: