sysutils/hcloud: update to 1.42.0

[uzsolt]

Summary

Uses GO 1.21.

Test Plan

With Go 1.20 doesn't build:

===>  Building hcloud from ./cmd/hcloud
internal/cmd/iso/list.go:5:2: package slices is not in GOROOT (/usr/local/go120/src/slices)
note: imported by a module that requires go 1.21
*** Error code 1

Portlint, portfmt, portclippy are ok.
Testport done on 13.2 and 14.0 amd64.

[diizzy]

Don't forgot to link to upstream changelog :-)