Update setup.py configuration

[huaibovip]

This pull request updates the setup.py script to improve the build process and packaging of the native library for the leapct PyTorch module. The changes streamline how the compiled library is handled across platforms and ensure it is correctly included in the package distribution.

Build process and packaging improvements:

• Unified the handling of build failures by moving the error check and exit logic after the platform-specific build commands, ensuring consistent behavior regardless of platform.
• Replaced platform-specific logic for copying the compiled library with a single shutil.copy call that places the built library into the src/leapct directory, simplifying the code and ensuring the library is always in the expected package location.
• Updated package_data to include the compiled library specifically within the leapct package and enabled include_package_data to ensure the library is distributed with the package.
• Removed the py_modules entry for modules that are now included via find_packages, preventing redundancy and potential packaging issues.