chore: Use giteabot instead of backporter (#37422)

This PR use a backporter wrap action
https://github.com/go-gitea/giteabot to do backport, adding labels and
etc. The test repository https://github.com/go-gitea/test-giteabot could
confirm backporting works.

---------

Signed-off-by: Lunny Xiao <xiaolunwen@gmail.com>
Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Nicolas <bircni@icloud.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.com>
Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>

.github/workflows/giteabot.yml

@@ -0,0 +1,44 @@
+name: giteabot
+
+on:
+  push:
+    branches:
+      - main
+  # pull_request_target gives this workflow access to GITEABOT_TOKEN on PRs from
+  # forks, which the bot needs to write labels, statuses and comments. Safe here
+  # because the job only runs a pinned action and never checks out PR HEAD.
+  pull_request_target: # zizmor: ignore[dangerous-triggers]
+    types:
+      - opened
+      - synchronize
+      - labeled
+      - unlabeled
+      - closed
+      - review_requested
+      - review_request_removed
+  pull_request_review:
+    types:
+      - submitted
+      - edited
+      - dismissed
+  schedule:
+    - cron: "15 3 * * *"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ format('{0}-{1}', github.workflow, (github.event_name == 'pull_request_target' || github.event_name == 'pull_request_review') && format('pr-{0}', github.event.pull_request.number) || 'maintenance') }}
+  cancel-in-progress: false
+
+jobs:
+  giteabot:
+    if: github.repository == 'go-gitea/gitea'
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: go-gitea/giteabot@8996d0b0e6c4ab066e3adcaf2c49b5d4cd15d7af # v1.0.1
+        with:
+          github_token: ${{ secrets.GITEABOT_TOKEN }}
+          gitea_fork: giteabot/gitea

docs/community-governance.md

@@ -48,7 +48,7 @@ If a PR has `lgtm/done`, no open discussions, and no merge conflicts, any mainta
 
 <https://github.com/go-gitea/gitea/pulls?q=is%3Apr+label%3Areviewed%2Fwait-merge+sort%3Acreated-asc+is%3Aopen>
 
-Gitea uses its own tool, <https://github.com/GiteaBot/gitea-backporter>, to automate parts of the review process. The backporter:
+Gitea uses its own tool, <https://github.com/go-gitea/gitea/blob/main/.github/workflows/giteabot.yml>, to automate parts of the review process. The backporter:
 
 - Creates a backport PR when needed after the initial PR merges.
 - Removes the PR from the merge queue after it merges.