CHORE: Clean up unused imports and fix cross-platform build script detection

- Remove unused 'sys' and 'Path' imports from build_backend.py
- Remove unused 'os' import from setup.py
- Fix find_pybind_dir() to check for platform-appropriate build script (build.bat on Windows, build.sh on Unix)

Author: bewithgaurav

build_ddbc/build_backend.py

@@ -11,9 +11,6 @@
     backend-path = ["."]
 """
 
-import sys
-from pathlib import Path
-
 # Import setuptools build backend - we'll wrap its functions
 from setuptools.build_meta import (
     build_wheel as _setuptools_build_wheel,

build_ddbc/compiler.py

@@ -63,12 +63,15 @@ def find_pybind_dir() -> Path:
         Path.cwd() / "mssql_python" / "pybind",
     ]
 
+    # Check for platform-appropriate build script
+    build_script = "build.bat" if sys.platform.startswith("win") else "build.sh"
+
     for path in possible_paths:
-        if path.exists() and (path / "build.sh").exists():
+        if path.exists() and (path / build_script).exists():
             return path
 
     raise FileNotFoundError(
-        "Could not find mssql_python/pybind directory. "
+        f"Could not find mssql_python/pybind directory with {build_script}. "
         "Make sure you're running from the project root."
     )
 

setup.py

@@ -14,7 +14,6 @@
     pip install -e .           # Editable install with auto-compile
 """
 
-import os
 import sys
 
 from setuptools import setup, find_packages