Add ArtifactDestroy GraphQL mutation

What does this MR do and why?

This MR adds a GraphQL mutation to allow deleting a job artifact, in order to support delivering #33418 (closed)

How to set up and validate locally

Until !96422 (merged) is merged, you'll need to use the rails console to find an artifact id.

Then use the artifact id with the mutation:

mutation {
  artifactDestroy(input:{
    id: "gid://gitlab/Ci::JobArtifact/293"
  }) {
    artifact {
      name
    }
  }
}

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.