Remove backportbot.yml

Issue gh-11736

.github/workflows/backport-bot.yml

@@ -1,33 +0,0 @@
-name: Backport Bot
-
-on:
-  issues:
-    types: [labeled]
-  pull_request:
-    types: [labeled]
-  push:
-    branches:
-      - '*.x'
-permissions:
-  contents: read
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    if: ${{ github.repository == 'spring-projects/spring-security' }}
-    permissions:
-      contents: read
-      issues: write
-      pull-requests: write
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-java@v3
-        with:
-          distribution: 'temurin'
-          java-version: '17'
-      - name: Download BackportBot
-        run: wget https://github.com/spring-io/backport-bot/releases/download/latest/backport-bot-0.0.1-SNAPSHOT.jar
-      - name: Backport
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          GITHUB_EVENT: ${{ toJSON(github.event) }}
-        run: java -jar backport-bot-0.0.1-SNAPSHOT.jar --github.accessToken="$GITHUB_TOKEN" --github.event_name "$GITHUB_EVENT_NAME" --github.event "$GITHUB_EVENT"