Test VERTX_5_STABLE_BRANCH variable

Author: vietj

.github/workflows/ci-5.x-stable.yml

@@ -7,7 +7,7 @@ on:
  branches:
  - '5.[0-9]+'
  schedule:
- - cron: '0 5 * * *'
+ - cron: '*/10 * * * *'
 jobs:
  CI-CD:
  uses: ./.github/workflows/ci-matrix-5.x.yml