Review remote_development route definitions, rewrite to eliminate unused routes
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## Description
The following discussion from !125331 should be addressed:
- [ ] @cwoolley-gitlab started a [discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/125331#note_1464756165):
> **issue (non-blocking)** We should revisit these route definitions, so that they only expose what we actually need.
>
> Currently, what we have here adds several routes that we don't use. Here's the output of `bin/rails routes`:
>
> ```
> remote_development_workspace_workspaces GET /-/remote_development/workspaces(/*vueroute)/:workspace_id/workspaces(.:format) remote_development/workspaces#index
> new_remote_development_workspace_workspace GET /-/remote_development/workspaces(/*vueroute)/:workspace_id/workspaces/new(.:format) remote_development/workspaces#index
> remote_development_workspaces GET /-/remote_development/workspaces(/*vueroute)(.:format) remote_development/workspaces#index
> POST /-/remote_development/workspaces(/*vueroute)(.:format) remote_development/workspaces#create
> new_remote_development_workspace GET /-/remote_development/workspaces(/*vueroute)/new(.:format) remote_development/workspaces#new
> edit_remote_development_workspace GET /-/remote_development/workspaces(/*vueroute)/:id/edit(.:format) remote_development/workspaces#edit
> remote_development_workspace GET /-/remote_development/workspaces(/*vueroute)/:id(.:format) remote_development/workspaces#show
> PATCH /-/remote_development/workspaces(/*vueroute)/:id(.:format) remote_development/workspaces#update
> PUT /-/remote_development/workspaces(/*vueroute)/:id(.:format) remote_development/workspaces#update
> DELETE /-/remote_development/workspaces(/*vueroute)/:id(.:format) remote_development/workspaces#destroy
>
> ```
>
> Let's create a follow-up backend issue to address cleaning this up.
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