Added pre-commit job (#1)

.github/workflows/build.yml

@@ -1,7 +1,6 @@
 name: "Build"
 on:
   pull_request:
-  push:
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -11,3 +10,23 @@ jobs:
       - run: nix build
       - run: nix flake check
       - run: nix run
+
+  pre-commit-hooks:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - uses: cachix/install-nix-action@v19
+
+      - run: echo "PY=$(python -VV | sha256sum | cut -d' ' -f1)" >> $GITHUB_ENV
+
+      - name: Cache pre-commit environment
+        uses: actions/cache@v3
+        with:
+          path: ~/.cache/pre-commit
+          key: pre-commit-${{ env.PY }}-${{ hashFiles('.pre-commit-config.yaml') }}
+
+      - name: Run pre-commit hooks
+        run: nix develop --command -- pre-commit run --show-diff-on-failure --color=always --from-ref origin/main --to-ref "$GITHUB_SHA"