target_commitish fails when set to the tag name

Octokit::UnprocessableEntity: POST https://api.github.com/repos/oneclick/rubyinstaller2/releases: 422 - Validation Failed (Octokit::UnprocessableEntity)
Error summary:
  resource: Release
  code: invalid
  field: target_commitish // See: https://docs.github.com/rest/releases/releases#create-a-release

Author: larskanis

lib/ruby_installer/build/release.rb

@@ -97,7 +97,6 @@ def upload_to_github(tag:, repo:, token: nil, files:)
       release = client.update_release(release.url, name: headline, body: body)
     else
       release = client.create_release(repo, tag,
-          target_commitish: tag,
           name: headline,
           body: body,
           draft: true,