Replace deprecated pkg_resources with importlib.metadata

pkg_resources (from setuptools) is deprecated and causes issues on
Python 3.12+ where it may not be available. Replace all usage with
importlib.metadata (stdlib since Python 3.8), with a fallback to the
importlib_metadata backport for older Python versions.

Fixes #1552

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ianhandy

setup.py

@@ -1,17 +1,20 @@
 #!/usr/bin/env python
 from setuptools import setup, find_packages
-import pkg_resources
 import sys
 import os
 import fastentrypoints
 
+try:
+    from importlib.metadata import version, PackageNotFoundError
+except ImportError:
+    from importlib_metadata import version, PackageNotFoundError
 
 try:
-    if int(pkg_resources.get_distribution("pip").version.split('.')[0]) < 6:
+    if int(version("pip").split('.')[0]) < 6:
         print('pip older than 6.0 not supported, please upgrade pip with:\n\n'
               '    pip install -U pip')
         sys.exit(-1)
-except pkg_resources.DistributionNotFound:
+except PackageNotFoundError:
     pass
 
 if os.environ.get('CONVERT_README'):

thefuck/utils.py

@@ -297,12 +297,10 @@ def wrapper(*args, **kwargs):
 def get_installation_version():
     try:
         from importlib.metadata import version
-
-        return version('thefuck')
     except ImportError:
-        import pkg_resources
+        from importlib_metadata import version
 
-        return pkg_resources.require('thefuck')[0].version
+    return version('thefuck')
 
 
 def get_alias():