rm submodule fetching workflow

.github/workflows/submodules.yml

@@ -1,20 +0,0 @@
-name: 'update submodules'
-
-on:
-  workflow_dispatch:
-
-jobs:
-  sync:
-    name: 'update submodules'
-    runs-on: ubuntu-latest
-    steps:
-      - name: checkout repo
-        uses: actions/checkout@v2
-        with:
-          submodules: true
-      - name: pull updates
-        run: |
-          git pull --recurse-submodules
-          git submodule update --remote --recursive
-      - name: commit changes
-        uses: stefanzweifel/git-auto-commit-action@v4