add CI-format workflow

.github/workflows/ci-format.yml

@@ -0,0 +1,23 @@
+# This is a format job. Pre-commit has a first-party GitHub action, so we use
+# that: https://github.com/pre-commit/action
+
+name: Format
+
+on:
+  workflow_dispatch:
+  pull_request:
+
+jobs:
+  pre-commit:
+    name: Format
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v4.7.0
+      with:
+        python-version: '3.10'
+    - name: Install system hooks
+      run: sudo apt install -qq clang-format-14 cppcheck
+    - uses: pre-commit/action@v3.0.0
+      with:
+        extra_args: --all-files --hook-stage manual