Security update for python-GitPython

This update for python-GitPython fixes the following issues - CVE-2026-42215: command injection via Git options bypass (bsc#1264604). - CVE-2026-42284: unsafe option check validates multi_options before shlex.split transforms it (bsc#1264605). - CVE-2026-44243: path traversal in GitPython reference APIs allows arbitrary file write and delete outside the repository (bsc#1264606). - CVE-2026-44244: newline injection in config_writer().set_value() enables RCE via core.hooksPath (bsc#1264608).