Group webhooks should be available for public groups on GitLab.com
Problem to solve
Some group-level features aren't available for public groups on GitLab.com. Public groups should receive Gold-level features by default, and we have issues to get group-level public features to Gold parity.
We should do this for group webhooks (see https://gitlab.com/groups/manage-sig/-/hooks for an example), which are currently a paid feature.
Proposal
Group webhooks should be available to public groups on GitLab.com