[installer] Make workspace garbage collection configurable

[andrew-farries]

Description

One of the Webapp team's epics for Q2 is to use the Gitpod installer to deploy to Gitpod SaaS. In order to do that we will need to add additional configuration to the installer to make the output suitable for a SaaS deployment as opposed to a self-hosted deployment.

This PR makes workspace garbage collection configurable by adding a new experimental.webapp.server.disableWorkspaceGarbageCollection flag to the installer config.

Related Issue(s)

Part of #9097

How to test

Create an installer config file containing this experimental section:

experimental:
  webapp:
    server:
      disableWorkspaceGarbageCollection: true

Get a versions.yaml for use with the installer:

docker run -it --rm "eu.gcr.io/gitpod-core-dev/build/versions:${version}" cat versions.yaml > versions.yaml

Then invoke the installer as:

go run . render --debug-version-file versions.yaml --config /path/to/config --use-experimental-config

The workspaceGarbageCollection.disabled field in the server config map will reflect the value set in the installer config.

Release Notes

Add `disableWorkspaceGarbageCollection` experimental installer config flag

Documentation

None.

[geropl]

👍

[Pothulapati]