git: ca6c9caa17b3..42df52d15694 - vendor/xz - vendor branch updated

[Xin LI]

The branch vendor/xz has been updated by delphij:

URL: https://cgit.FreeBSD.org/src/log/?id=ca6c9caa17b3..42df52d15694

42df52d15694 Vendor import of xz 5.4.4 (trimmed)