Design: UX for creating Workspaces on CI Runners
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## Description
What the the UX considerations to be made as we run Workspaces on CI Runners?
- e.g. how should the "select the agent" dropdown on workspace creation behave?
- e.g. when a workspace is created, do we want to show how it was created during the listing? through Kubernetes or through CI runner?
- e.g. what does the workspaces settings page in group settings explicitly distinguish that those settings are only for the Kubernetes approach? Same for the instance/organization level settings for mapping an agent for the Kubernetes approach.
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## Acceptance criteria
- [ ] Designs for the UI changes
## Implementation plan
N.A.
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