chore: remove namespace restriction for GovDAO votes

[Kouteki]

Description

We want to retain the concept of namespaces (i.e. enforcing that realm package paths are prefixed by a registered username or address), but we no longer want the r/gnoland/names realm as the authority for that.

Going forward, only address-prefix namespaces are valid until a proper names realm is designed and approved via GovDAO governance.

This means that we need to roll back the namespace requirement for GovDAO voting.

Acceptance criteria

• Update GovDAO so it no longer requires members to have a registered username