deskutils/ultralist: fix build on riscv64

Bump golang.org/x/sys dependency to a version new enough
to support riscv64-freebsd.

While we are at it, remove useless GH_TUPLE entries.
Upstream already vendors these dependencies, so the
entries never affected the build in the first place.

Sponsored by: Berliner Linux User Group e.V.
Approved by: portmgr (build fix blanket)
Differential Revision: https://reviews.freebsd.org/D38997