Use pre-commit action directly to run flake8 and black, instead of fl…

…ake8 action.

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ env:
   PYTEST_ADDOPTS: --color=yes
 
 jobs:
-  flake8-lint:
+  lint:
     runs-on: ubuntu-latest
     name: Lint
     steps:
@@ -23,19 +23,22 @@ jobs:
       - name: Set up Python environment
         uses: actions/setup-python@v4
         with:
-          python-version: "3.8"
-      - name: flake8 Lint
-        uses: py-actions/flake8@v2 
+          python-version: "3.9"
+      - name: Runs pre-commit hooks
+        uses: pre-commit/action@v3.0.0
+        with:
+          extra_args: --files $(git diff origin/main --name-only)
 
   tests:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8, 3.9, "3.10", 3.11]
+        python-version: ["3.8", "3.9", "3.10", "3.11"]
         ctapipe-version: [v0.19.1]
 
     defaults:
       run:
+        # We need login shells (-l) for micromamba to work.
         shell: bash -leo pipefail {0}
 
     steps: