Docling Core vulnerable to Remote Code Execution via unsafe PyYAML usage

Docling Core (or docling-core) is a library that defines core data types and transformations in the document processing application Docling. A PyYAML-related Remote Code Execution (RCE) vulnerability, namely CVE-2020-14343, is exposed in docling-core starting in version 2.21.0 and prior to version 2.48.4, specifically only if the application uses pyyaml prior to version 5.4 and invokes `docling_core.types.doc.DoclingDocument.load_from_yaml()` passing it untrusted YAML data. The vulnerability has been patched in docling-core version 2.48.4. The fix mitigates the issue by switching `PyYAML` deserialization from `yaml.FullLoader` to `yaml.SafeLoader`, ensuring that untrusted data cannot trigger code execution. Users who cannot immediately upgrade docling-core can alternatively ensure that the installed version of PyYAML is 5.4 or greater.