Update deprecated autoflake hook (#386)

As stated in https://github.com/humitos/mirrors-autoflake/blob/master/README.md, DO NOT USE THIS REPOSITORY. There is an official version now at https://github.com/PyCQA/autoflake/blob/master/.pre-commit-hooks.yaml.

There are some errors when using this deprecated hook under Python 3.12,
such as

Traceback (most recent call last):
  File "/home/fanta/.cache/pre-commit/repoo2mq6vmn/py_env-python3.12/bin/autoflake", line 5, in <module>
    from autoflake import main
  File "/home/fanta/.cache/pre-commit/repoo2mq6vmn/py_env-python3.12/lib/python3.12/site-packages/autoflake.py", line 32, in <module>
    import distutils.sysconfig
ModuleNotFoundError: No module named 'distutils'

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
-  - repo: https://github.com/humitos/mirrors-autoflake
-    rev: v1.1
+  - repo: https://github.com/PyCQA/autoflake
+    rev: v2.3.1
     hooks:
       - id: autoflake
         args: ["-i", "--remove-all-unused-imports"]