Explicitly install pre-commit hooks as its own step so it's clearer when the

failure is with setup rather than hooks running.

.github/workflows/build.yml

@@ -42,5 +42,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install --upgrade --requirement requirements-test.txt
+      - name: Install pre-commit hooks
+        run: pre-commit install-hooks
       - name: Run pre-commit on all files
         run: pre-commit run --all-files