Expose Public API in Staging on SaaS

[easyCZ]

So far we've only configured Public API to be deployed in Preview Environments. We would like to also deploy it in staging environments.

This entails adding the experimeental.webApp.publicApi config to the staging deployment such that it gets deployed.

Acceptance Criteria:

• Public API deployed in staging
• Public API is reachable

[easyCZ]

This is how we enabled it in preview: #9260

[easyCZ]

https://github.com/gitpod-io/ops/pull/2190 enables the public api

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.