Create workspaces container image for the Web IDE project.

What does this MR do and why?

What It creates a Workspaces container image that includes tools required by the Web IDE project.

why We want to promote more dogfooding of Workspaces across the organization. The Web IDE is a great project to get started because it's a simple node-based application.

Checklist

• (If applicable) Add patches if required for upgrading Ruby version in https://gitlab.com/gitlab-org/gitlab-build-images/-/tree/master/patches/ruby.

Screenshots or videos

workspaces_web_ide_demo_720p.mov

How to test?

You can create a Workspace that uses this MR's branch gitlab-web-ide!423 (merged) as the base ref. I pushed the image manually to the Web IDE's container registry because this project doesn't push images to its container registry from the CI pipeline.