fix: remove auto merge github action

.github/workflows/branch-merge.yml

@@ -1,18 +0,0 @@
-name: Merge Branch
-
-on:
-  push:
-    branches: [imgbot]
-
-jobs:
-  merge-branch:
-    runs-on: ubuntu-latest
-    if: github.repository == 'doocs/advanced-java'
-    steps:
-      - uses: actions/checkout@v2
-      - uses: everlytic/branch-merge@1.1.0
-        with:
-          github_token: ${{ github.token }}
-          source_ref: ${{ github.ref }}
-          target_branch: main
-          commit_message_template: "[Automated] Merged {source_ref} into {target_branch}"