Add code-format gh action

Signed-off-by: Thomas Frank <[email protected]>

.github/workflows/format.yml

@@ -0,0 +1,39 @@
+name: Code format check
+
+on: pull_request
+
+jobs:
+  treefmt:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Create user program directory
+        run: |
+          mkdir -p $HOME/.local/bin
+          echo "$HOME/.local/bin" >> "$GITHUB_PATH"
+
+      - name: Install treefmt
+        run: |
+          curl -L https://github.com/numtide/treefmt/releases/download/v2.0.5/treefmt_2.0.5_linux_amd64.tar.gz -o treefmt.tar.gz
+          tar -xvzf treefmt.tar.gz
+          install -m 755 treefmt $HOME/.local/bin
+          rm LICENSE README.md treefmt treefmt.tar.gz
+
+      - name: Install clang-format
+        run: |
+          curl -L https://github.com/muttleyxd/clang-tools-static-binaries/releases/download/master-32d3ac78/clang-format-17_linux-amd64 -o clang-format
+          install -m 755 clang-format $HOME/.local/bin
+          rm clang-format
+
+      - uses: actions/setup-python@v5
+
+      - name: Install cmake-format
+        run: |
+          pip install cmakelang
+
+      - uses: actions/checkout@v4
+
+      - name: Check code format
+        continue-on-error: true
+        run: |
+          treefmt
+          git diff --exit-code