remove github action

.github/workflows/shfmt.yml

@@ -1,14 +0,0 @@
-name: sh-checker
-on:
-  - pull_request
-jobs:
-  sh-checker:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v1
-      - name: Run the sh-checker
-        uses: luizm/action-sh-checker@v0.1.7
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          sh_checker_comment: true