removeLabel = async (octokit, prNumber, owner, repo, label) => {
  await octokit.rest.issues.removeLabel({
    owner,
    repo,
    issue_number: prNumber,
    name: label,
  });
}
Remove label from the pull request.

@param {Object} octokit Octokit instance.
@param {number} prNumber Pull request number.
@param {string} owner Repository owner.
@param {string} repo Repository name.
@param {string} label Label to add or remove.
@returns {Promise<void>} Promise.