fix: unable to locate package createrepo (#243)

* test ubuntu 1804

* fix(ci): unable to locate package createrepo

Co-authored-by: soulbird <[email protected]>

Author: soulbird

.github/workflows/publish.yml

@@ -10,7 +10,7 @@ concurrency:
 jobs:
   publish_apisix:
     name: Build and Publish RPM Package
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-18.04
     timeout-minutes: 60
     env:
       VAR_COS_BUCKET_CI: ${{ secrets.VAR_COS_BUCKET_CI }}