_pkg.sh: use POSIX.1-1988 tar format (ustar) [ci skip]
_pkg.sh: use POSIX.1-1988 tar format (ustar) [ci skip]

This will change all archiv hashes on the next build.

Ref: https://seclists.org/oss-sec/2021/q4/0

vszakats/harbour-deps,vszakats/harbour-deps