Combine the CI and precommit workflows.

Author: Julian

.github/workflows/ci.yml

@@ -10,6 +10,13 @@ on:
     - cron: '21 3 * * *'
 
 jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+    - uses: pre-commit/[email protected]
+
   ci:
     runs-on: ${{ matrix.os }}
     strategy: