Use single source of truth for version from pyproject.toml

Replace hardcoded module metadata in maxminddb/__init__.py with
importlib.metadata.version() to get the version from pyproject.toml.
This eliminates duplication and makes pyproject.toml the single source
of truth for package metadata.

Changes:
- Remove __title__, __author__, __license__, and __copyright__ from
  __init__.py (redundant with pyproject.toml)
- Replace hardcoded __version__ with importlib.metadata.version()
- Remove version reading from setup.py (setuptools gets it from
  pyproject.toml automatically)
- Update dev-bin/release.sh to only update pyproject.toml version

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: oschwald

dev-bin/release.sh

@@ -33,7 +33,6 @@ if [ -n "$(git status --porcelain)" ]; then
     exit 1
 fi
 
-perl -pi -e "s/(?<=__version__ = \").+?(?=\")/$version/gsm" maxminddb/__init__.py
 perl -pi -e "s/(?<=^version = \").+?(?=\")/$version/gsm" pyproject.toml
 
 echo $"Test results:"

maxminddb/__init__.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+from importlib.metadata import version
 from typing import IO, TYPE_CHECKING, AnyStr, cast
 
 from .const import (
@@ -87,8 +88,4 @@ def open_database(
     return cast("Reader", _extension.Reader(database, mode))
 
 
-__title__ = "maxminddb"
-__version__ = "2.8.2"
-__author__ = "Gregory Oschwald"
-__license__ = "Apache License, Version 2.0"
-__copyright__ = "Copyright 2013-2025 MaxMind, Inc."
+__version__ = version("maxminddb")

setup.py

@@ -1,5 +1,4 @@
 import os
-import re
 import sys
 
 from setuptools import Extension, setup
@@ -93,20 +92,6 @@ def build_extension(self, ext) -> None:
 cmdclass["build_ext"] = ve_build_ext
 
 
-ROOT = os.path.dirname(__file__)
-
-with open(os.path.join(ROOT, "README.rst"), encoding="utf-8") as fd:
-    README = fd.read()
-
-with open(os.path.join(ROOT, "maxminddb", "__init__.py"), encoding="utf-8") as fd:
-    maxminddb_text = fd.read()
-    VERSION = (
-        re.compile(r".*__version__ = \"(.*?)\"", re.DOTALL)
-        .match(maxminddb_text)
-        .group(1)
-    )
-
-
 def status_msgs(*msgs):
     print("*" * 75)
     for msg in msgs:
@@ -131,7 +116,7 @@ def run_setup(with_cext) -> None:
         kwargs["ext_modules"] = ext_module
         loc_cmdclass["bdist_wheel"] = bdist_wheel
 
-    setup(version=VERSION, cmdclass=loc_cmdclass, **kwargs)
+    setup(cmdclass=loc_cmdclass, **kwargs)
 
 
 try: