refactor: remove redundant version parsing from setup.py

setuptools automatically reads version from pyproject.toml's
tool.setuptools.dynamic.version configuration. Manual regex
parsing was unnecessary duplication.

Author: devjerry0

setup.py

@@ -1,15 +1,5 @@
-import re
-from pathlib import Path
-
 from setuptools import find_packages, setup
 
-version_file = Path(__file__).parent / "contractions" / "_version.py"
-version_content = version_file.read_text()
-version_match = re.search(r'^__version__\s*=\s*[\'"]([^\'"]*)[\'"]', version_content, re.M)
-if not version_match:
-    raise RuntimeError("Unable to find version string.")
-VERSION = version_match.group(1)
-
 setup(
     packages=find_packages(exclude=["tests", "tests.*"]),
     package_data={