GraphQL: Implement CiRunnerType.upgradeStatus

What does this MR do and why?

Describe in detail what your merge request does and why.

This MR exposes an upgradeStatus property in the GraphQL CiRunnerType object. It leverages the recently-introduced Gitlab::Ci::RunnerUpgradeCheck service to determine whether a specified version needs up update or not.

Screenshots or screen recordings

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Ensure that you have at least one GitLab Runner installed

2. Open http://gdk.test:3000/-/graphql-explorer and execute the following query:

   {
     runners {
       nodes {
         id
           description
           version
           upgradeStatus
       }
     }
   }

Expected response should contain a meaningful upgradeStatus value:

{
  "data": {
    "runners": {
      "nodes": [
      {
        "id": "gid://gitlab/Ci::Runner/1",
          "description": "Project test runner",
          "version": "14.10.0~beta.6.g6c90c3ff",
          "upgradeStatus": "NOT_AVAILABLE"
      }
      ]
    }
  }
}

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.

Closes #356671 (closed)