pre-commit: Bump hooks and add new one to check commit message spelling

To install the new hook:

  $ pre-commit install -t commit-msg

.pre-commit-config.yaml

@@ -1,50 +1,43 @@
 repos:
-- repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v2.4.0
-  hooks:
-  - id: trailing-whitespace
-  - id: check-json
-  - id: check-yaml
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.1.0
+    hooks:
+      - id: trailing-whitespace
+      - id: check-json
+      - id: check-yaml
 
-- repo: https://gitlab.com/pycqa/flake8
-  rev: 3.8.3
-  hooks:
-  - id: flake8
+  - repo: https://gitlab.com/pycqa/flake8
+    rev: 4.0.1
+    hooks:
+      - id: flake8
 
-- repo: https://github.com/codespell-project/codespell
-  rev: v1.16.0
-  hooks:
-  - id: codespell
-    exclude: ^(swh/lister/.*/tests/data/.*)$
+  - repo: https://github.com/codespell-project/codespell
+    rev: v2.1.0
+    hooks:
+      - id: codespell
+        name: Check source code spelling
+        exclude: ^(swh/lister/.*/tests/data/.*)$
+        stages: [commit]
+      - id: codespell
+        name: Check commit message spelling
+        stages: [commit-msg]
 
-- repo: local
-  hooks:
-  - id: mypy
-    name: mypy
-    entry: mypy
-    args: [swh]
-    pass_filenames: false
-    language: system
-    types: [python]
+  - repo: local
+    hooks:
+      - id: mypy
+        name: mypy
+        entry: mypy
+        args: [swh]
+        pass_filenames: false
+        language: system
+        types: [python]
 
-- repo: https://github.com/PyCQA/isort
-  rev: 5.5.2
-  hooks:
-  - id: isort
-
-- repo: https://github.com/python/black
-  rev: 19.10b0
-  hooks:
-  - id: black
-
-# unfortunately, we are far from being able to enable this...
-# - repo: https://github.com/PyCQA/pydocstyle.git
-#   rev: 4.0.0
-#   hooks:
-#   - id: pydocstyle
-#     name: pydocstyle
-#     description: pydocstyle is a static analysis tool for checking compliance with Python docstring conventions.
-#     entry: pydocstyle --convention=google
-#     language: python
-#     types: [python]
+  - repo: https://github.com/PyCQA/isort
+    rev: 5.10.1
+    hooks:
+      - id: isort
 
+  - repo: https://github.com/python/black
+    rev: 19.10b0
+    hooks:
+      - id: black