net/unfs3: update to 0.9.23

ChangeLog: https://github.com/unfs3/unfs3/blob/master/NEWS

• include AFS support for better serving of files from AFS filesystems
• use svc_getreq_poll() when available
• fix serving files larger than 4GB from Windows
• better support for 64-bit systems
• fixes for macOS and Windows support
• fixes when cross compiling
• better support for exporting FAT filesystems

PR: 267848
Reported by: fuz@fuz.su (maintainer)
MFH: 2022Q4 (bugfix release)

(cherry picked from commit c6dc382584dcee8bca54884ec217c73f9ac621c3)