BIT-python-min-2026-7774: tarfile.data_filter path traversal bypass allows writing outside the extraction directory

tarfile.datafilter could be bypassed using crafted link entries, including symlinks with empty or directory-like names, to redirect later archive members outside the intended extraction directory. This allowed a malicious tar archive to cause tarfile.extractall() to write files outside the destination directory, subject to the permissions of the extracting process.