chore: remove prettier workflow

.github/workflows/prettier.yml

@@ -1,23 +0,0 @@
-name: Prettier
-
-on:
-  push:
-    branches: [main]
-
-jobs:
-  prettier:
-    runs-on: ubuntu-latest
-    if: github.repository == 'doocs/advanced-java'
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-        with:
-          ref: ${{ github.head_ref }}
-
-      - name: Prettify
-        uses: creyD/prettier_action@v3.3
-        with:
-          prettier_options: --write **/*.{md}
-          commit_message: "style: prettify code or document"
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}