Draft: POC for using runners to provision workspaces

Issue: Investigate Alternatives to Kubernetes for Work... (gitlab-org/gitlab#505764 - closed)

What does this MR do and why?

Draft: POC for using runners to provision workspaces

Related to gitlab-org/gitlab#505764 (closed)

How to test it

1. cd <to-the-agent-project>
2. GOOS=linux GOARCH=amd64 go build ./cmd/agentk
3. cd <to-this-project>
4. cp <to-the-agent-project>/agentk agentk
5. OS=linux PLATFORM=amd64 ENV=local make docker-build-and-publish
6. docker run -p 60001:60001 -e 'GL_TOOLS_DIR=/tmp/.gl-tools' --platform linux/amd64 -it --rm registry.gitlab.com/gitlab-org/workspaces/gitlab-workspaces-tools:latest /bin/bash
7. ./copy_tools.sh
8. ./init_tools.sh

MR acceptance checklist

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Before	After

How to set up and validate locally

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