Remove security tracked-refs local GraphQL types

What does this MR do and why?

Remove security tracked-refs local GraphQL types

Currently, we use a local resolver to mock the UI for the new security configuration section to set up tracked refs.

But the BE is currently being added, so the types need to be removed to avoid failing pipelines duo to types being defined twice. Since the types are not strictly needed for the client-side resolver, they can be removed without any consequences.

Screenshots or screen recordings

No visible changes

How to set up and validate locally

1. Enable the feature flag (http://gdk.test:3000/rails/features/vulnerabilities_across_contexts)
2. Navigate to a project's security configuration and then the "Vulnerability Management" tab
3. Verify that there are no errors when the page is loaded and that the "Refs" Section is rendered correctly
4. Disable the feature flag
5. Verify that there are no errors when the page is loaded and that the section is not visible

MR acceptance checklist

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