Docling: METS-GBS archive member limit enforced after full member enumeration (memory exhaustion during format detection)

Summary When docling detects the input format of a gzip-compressed tar archive METS-GBS, and later when the METS-GBS backend opens it, it calls tarfile.TarFile.getmembers. That builds the full member list in memory before the maxmembercount limit is checked. A small archive with a very large numb...