fix(deps): remove replace directive for github.com/openark/golib

[dnwe]

As part of DISTMYSQL-157 the github.com/openark/golib module was forked into a go/golib subdirectory of orchestrator and used via a top-level replace directive with a dummy go.mod under go/golib/go.mod. With orchestrator now forked away from openark it is cleaner to just update the import paths and use the in-tree packages directly rather than via a replace directive.