Add pre-commit hooks for Python code

.pre-commit-config.yaml

+# Copyright (c) 2013-2024 MPI-M, Luis Kornblueh, Rahul Sinha and DWD, Florian Prill. All rights reserved.
+#
+# SPDX-License-Identifier: CC0-1.0
+#
+
+repos:
+  - repo: https://github.com/pycqa/isort
+    rev: 5.13.2
+    hooks:
+      - id: isort
+      - id: isort
+        name: isort (templates)
+        types_or: [file]
+        files: (python\.sh|\.py)\.in$
+  - repo: https://github.com/psf/black-pre-commit-mirror
+    rev: 24.10.0
+    hooks:
+      - id: black
+      - id: black
+        name: black (templates)
+        types_or: [file]
+        files: (python\.sh|\.py)\.in$
+  - repo: https://github.com/csachs/pyproject-flake8
+    rev: v7.0.0
+    hooks:
+      - id: pyproject-flake8
+      - id: pyproject-flake8
+        name: pyproject-flake8 (templates)
+        types: [file]
+        files: (python\.sh|\.py)\.in$