ci: add CLA workflow with bot allowlist to replace cla-assistant.io webhook

Agent-Logs-Url: https://github.com/cloudwego/cloudwego.github.io/sessions/9922d0ff-6cb3-480b-8137-2d2f8edbc328

Co-authored-by: GuangmingLuo <16001996+GuangmingLuo@users.noreply.github.com>

Author: Copilot

.github/workflows/cla.yml

@@ -0,0 +1,28 @@
+name: CLA Assistant
+
+on:
+  issue_comment:
+    types: [created]
+  pull_request_target:
+    types: [opened, closed, synchronize]
+
+permissions:
+  actions: write
+  contents: write
+  pull-requests: write
+  statuses: write
+
+jobs:
+  CLAssistant:
+    runs-on: ubuntu-latest
+    steps:
+      - name: CLA Assistant
+        uses: contributor-assistant/github-action@v2.6.1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          PERSONAL_ACCESS_TOKEN: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
+        with:
+          path-to-signatures: signatures/version1/cla.json
+          path-to-document: https://cla-assistant.io/cloudwego/cloudwego.github.io
+          branch: main
+          allowlist: bot

signatures/version1/cla.json

@@ -0,0 +1 @@
+{ "signedContributors": [] }