Use buf-action in CI

.github/workflows/buf-ci.yaml

@@ -0,0 +1,27 @@
+name: Buf CI
+on:
+  push:
+    paths:
+      - buf.yaml
+      - buf.lock
+      - 'proto/**'
+      - '.github/workflows/buf-ci.yaml'
+  pull_request:
+    paths:
+      - buf.yaml
+      - buf.lock
+      - 'proto/**'
+      - '.github/workflows/buf-ci.yaml'
+    types: [opened, synchronize, reopened, labeled, unlabeled]
+  delete:
+permissions:
+  contents: read
+  pull-requests: write
+jobs:
+  buf:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: bufbuild/buf-action@v0.1
+        with:
+          token: ${{ secrets.BUF_TOKEN }}