ci: migrate auto-merge to gh cli

- Add `contents: write` permission to the workflow
- Update token reference from `secrets.GITHUB_TOKEN` to `${{ github.token }}`
- Remove `Auto_Merge_PR` job and associated steps
- Add environment variable `GH_TOKEN` and merge pull request using `gh` command in the `Auto_Approve` job

Signed-off-by: 陳鈞 <[email protected]>

.github/workflows/AutoMerge.yml

@@ -6,6 +6,7 @@ permissions:
   # Permission to trigger the minify workflow
   actions: write
   pull-requests: write
+  contents: write
 
 jobs:
   Auto_Approve:
@@ -18,25 +19,13 @@ jobs:
       - name: Auto approve
         uses: hmarr/auto-approve-action@v4
         with:
-          github-token: "${{ secrets.GITHUB_TOKEN }}"
+          github-token: "${{ github.token }}"
 
-  Auto_Merge_PR:
-    name: Auto Merge PR
-    runs-on: ubuntu-latest
-    needs: "Auto_Approve"
-    steps:
       - name: Git Auto Merge
-        uses: plm9606/[email protected]
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          merge-method: merge
-          reviewers-number: 0
-          label-name: "automerge"
-
-      - name: Remove label
-        if: ${{ success() }}
-        uses: buildsville/[email protected]
-        with:
-          token: ${{secrets.GITHUB_TOKEN}}
-          label: "automerge"
-          type: remove
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          gh pr merge --merge \
+                      --auto \
+                      ${{ github.event.pull_request.number }} \
+        shell: bash