build: Update project URLs and streamline package versioning This commit updates the project's public URLs in `pyproject.toml` from GitLab to GitHub, including Homepage, Repository, and Issues links. Additionally, it streamlines the package versioning process: - The `.github/workflows/build-pypi-package.yml` workflow no longer writes the version to `auto_commit_ai/_version.py`. - The `pyproject.toml` configuration is updated to reflect this, removing the explicit lookup of `__version__` from the `_version.py` file. This change simplifies the release build process by relying directly on the Git tag for package versioning.