ci: sync with template repository

.github/auto-label.yaml

@@ -0,0 +1,11 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/googleapis/repo-automation-bots/main/packages/auto-label/src/config-schema.json
+
+language:
+  pullrequest: true
+  labelprefix: "lang: "
+
+staleness:
+  pullrequest: true
+
+requestsize:
+  enabled: true

.github/blunderbuss.yml

@@ -0,0 +1,10 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/googleapis/repo-automation-bots/main/packages/blunderbuss/src/config-schema.json
+
+assign_issues:
+  - liblaf
+
+assign_prs:
+  - liblaf
+
+ignore_authors:
+  - dependabot

.github/workflows/merge.yaml

@@ -3,10 +3,6 @@ name: Merge
 on:
   pull_request:
 
-permissions:
-  contents: write
-  pull-requests: write
-
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
 
@@ -20,6 +16,8 @@ jobs:
 
   merge:
     name: Merge
+    permissions:
+      pull-requests: write
     if: github.event.pull_request.user.login == 'dependabot[bot]' ||
       github.event.pull_request.user.login == 'pre-commit-ci[bot]'
     runs-on: ubuntu-latest
@@ -28,3 +26,8 @@ jobs:
         run: gh pr merge ${{ github.event.pull_request.html_url }} --auto --squash
         env:
           GH_TOKEN: ${{ github.token }}
+      - name: Enable Merge-on-green
+        run: |
+          gh pr edit ${{ github.event.pull_request.html_url }} --add-label "automerge: exact"
+        env:
+          GH_TOKEN: ${{ github.token }}