install astyle with nix in ci workflow

Signed-off-by: Thing-han, Lim <[email protected]>

.github/workflows/build.yaml

@@ -8,8 +8,20 @@ jobs:
   build_test:
     runs-on: ubuntu-latest
     steps:
+    - id: nixpkgs
+      shell: bash
+      run: |
+        if [ -f flake.lock ]; then
+          nixpkgs="flake:$(cat flake.lock | jq -r '.nodes.nixpkgs.locked // empty | .type + ":" + .owner + "/" + .repo + "/" + .rev')"
+        else
+          nixpkgs=channel:nixos-unstable
+        fi
+        echo "nixpkgs=$nixpkgs" >> "$GITHUB_OUTPUT"
+    - uses: cachix/install-nix-action@v25
+      with:
+        nix_path: nixpkgs=${{ steps.nixpkgs.outputs.nixpkgs }}
     - uses: actions/checkout@v3
     - name: install dependencies
-      run: sudo apt install astyle
+      run: nix profile install nixpkgs#astyle
     - name: Astyle
-      run: astyle **/*.[ch] --options=.astylerc --dry-run | grep -vq "Formatted"
+      run: astyle **/*.[ch] --options=.astylerc --dry-run | grep -vq "Formatted"