filesystems/nbt: Update 20250506 => 20260630

This update includes several memory-access bug fixes in both the NBT
library and the file system implementations, more completed supports
for the TAG_LONG_ARRAY type in the library, revised manual pages, as
well as other minor improvements.

Commit log:
https://src.rivoreo.one/nbtfsutils/+log/c06da0c1e1b5da7140171cb5a2138d2fe1197a63/

PR: 296479
Reported by: WHR <whr@rivoreo.one> (maintainer)
Approved by: osa, vvd (Mentors, implicit)
MFH: 2026Q3