Bump pre-commit hook versions

This is the result of running `pre-commit autoupdate`. The new version
of the `flake8` pre-commit hook requires a Python version >= 3.8.1, so
it was necessary to add the `language_version: python3.8` line. Since
`egon-data` also supports Python 3.7, this makes sure that a suitable
interpreter version is chosen to run the pre-commit hook.

.pre-commit-config.yaml

@@ -5,21 +5,22 @@
 exclude: '^(\.tox|ci/templates|\.bumpversion\.cfg)(/|$)'
 repos:
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v4.3.0
+    rev: v4.4.0
     hooks:
       - id: trailing-whitespace
       - id: end-of-file-fixer
       - id: debug-statements
   - repo: https://github.com/timothycrosley/isort
-    rev: 5.10.1
+    rev: 5.11.4
     hooks:
       - id: isort
   - repo: https://github.com/psf/black
-    rev: 22.8.0
+    rev: 22.12.0
     hooks:
       - id: black
         language_version: python3 # Should be a command that runs python3.6+
   - repo: https://github.com/pycqa/flake8
-    rev: 5.0.4
+    rev: 6.0.0
     hooks:
       - id: flake8
+        language_version: python3.8