Add clang-format check action

.github/workflows/check-clang-format.yml

@@ -0,0 +1,27 @@
+name: Clang-format
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  clang-format:
+    name: Check clang-format
+    runs-on: ubuntu-latest
+    container: archlinux:latest
+    steps:
+      - name: Cache pacman packages
+        uses: actions/cache@v4
+        with:
+          path: '/var/cache/pacman/pkg'
+          key: ${{ runner.os }}-pacman
+      - name: Install dependencies
+        run: |
+          pacman -Syu --noconfirm git clang diffutils
+          git config --global --add safe.directory $GITHUB_WORKSPACE
+      - uses: actions/checkout@v4
+      - uses: fcitx/github-actions@clang-format