Run pre-commit in GitHub Actions (#17)

* Run pre-commit in GitHub Actions

* Don't run pre-commit from Python

* Review feedback

.github/workflows/lint.yaml

@@ -0,0 +1,25 @@
+name: Lint
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.10'
+      - name: Lint
+        run: ./ci/lint.sh

ci/lint.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+# Runs pre-commit
+
+set -ue
+
+pip install pre-commit
+
+pre-commit run --all-files --show-diff-on-failure