[CI] run CompatHelper with default Julia version

Author: johnnychen94

.github/workflows/CompatHelper.yml

@@ -2,22 +2,12 @@ name: CompatHelper
 
 on:
   schedule:
-    - cron: '20 00 * * *'
-  issues:
-    types: [opened, reopened]
+    - cron: '00 00 * * *'
 
 jobs:
-  build:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        julia-version: [1.2.0]
-        julia-arch: [x86]
-        os: [ubuntu-latest]
+  CompatHelper:
+    runs-on: ubuntu-latest
     steps:
-      - uses: julia-actions/setup-julia@latest
-        with:
-          version: ${{ matrix.julia-version }}
       - name: Pkg.add("CompatHelper")
         run: julia -e 'using Pkg; Pkg.add("CompatHelper")'
       - name: CompatHelper.main()