net/nncp: Update 8.8.1 => 8.8.3
Changelog:
http://www.nncpgo.org/Release-8_005f8_005f2.html
http://www.nncpgo.org/Release-8_005f8_005f3.html
Switch to go 1.21, but build still fails with go 1.22+.
PR: 289697
Approved by: Sergey Matveev <stargrave@stargrave.org> (maintainer)
MFH: 2025Q3