Handle possible Github API rejection at prepareItemStep

[LearningProcesss]

GithubSyncService's pipeline must catch possible rejections when fetching repo's commits and languages during prepareItemStep.

RequestError [HttpError]: Repository access blocked
    at /workspaces/better-gh-watched/node_modules/@octokit/request/dist-node/index.js:86:21
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Job.doExecute (/workspaces/better-gh-watched/node_modules/bottleneck/light.js:405:18) {
  status: 451,
  response: {
    url: 'https://api.github.com/repos/arifnoumankhan/books/commits?page=1&per_page=1',
    status: 451,
    headers: {
      'access-control-allow-origin': '*',
      'access-control-expose-headers': 'ETag, Link, Location, Retry-After, X-GitHub-OTP, X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Used, X-RateLimit-Resource, X-RateLimit-Reset, X-OAuth-Scopes, X-Accepted-OAuth-Scopes, X-Poll-Interval, X-GitHub-Media-Type, X-GitHub-SSO, X-GitHub-Request-Id, Deprecation, Sunset',
      connection: 'close',
      'content-length': '187',
      'content-security-policy': "default-src 'none'",
      'content-type': 'application/json; charset=utf-8',
      date: 'Fri, 07 Jan 2022 17:43:04 GMT',
      'referrer-policy': 'origin-when-cross-origin, strict-origin-when-cross-origin',
      server: 'GitHub.com',
      'strict-transport-security': 'max-age=31536000; includeSubdomains; preload',
      vary: 'Accept-Encoding, Accept, X-Requested-With',
      'x-accepted-oauth-scopes': '',
      'x-content-type-options': 'nosniff',
      'x-frame-options': 'deny',
      'x-github-media-type': 'github.v3; format=json',
      'x-github-request-id': 'D7D5:1112:4873A2:4AF060:61D87BA8',
      'x-oauth-client-id': '7960cb405d3d74742e13',
      'x-oauth-scopes': 'user:email',
      'x-ratelimit-limit': '5000',
      'x-ratelimit-remaining': '3730',
      'x-ratelimit-reset': '1641579822',
      'x-ratelimit-resource': 'core',
      'x-ratelimit-used': '1270',
      'x-xss-protection': '0'
    },
    data: {
      message: 'Repository access blocked',
      block: {
        reason: 'dmca',
        created_at: '2020-07-23T20:32:55Z',
        html_url: 'https://github.com/github/dmca/blob/master/2020/07/2020-07-22-Oreilly.md'
      }
    }
  },
  request: {
    method: 'GET',
    url: 'https://api.github.com/repos/arifnoumankhan/books/commits?page=1&per_page=1',
    headers: {
      accept: 'application/vnd.github.v3+json',
      'user-agent': 'octokit-rest.js/1.7.1 octokit-core.js/3.5.1 Node.js/16.13.0 (linux; x64)',
      authorization: 'token [REDACTED]'
    },
    request: {
      hook: [Function: bound bound register],
      retryCount: 3,
      retries: 3,
      retryAfter: 16
    }
  }
}