dns/zns: Update 0.3.0 => 0.4.0

While here, remove go version from USES
since it's already the default version.
In case it was the opposite, it's OK
too because go is backwards-compatible.

Changelog:
https://github.com/znscli/zns/releases/tag/v0.4.0

PR:		289446
Reported by:	portscout
Approved by:	yuri@ (Mentor)