Create Status check fails when the markdown is too long

[sreejith-kulamgarath]

GitHub API has a limit of 65535 characters. We already have this check when creating the PR comment.

However, this check is missing in the createStatusCheck method. If the markdown length is over 65535^[1], the api fails with no useful error message.

We should do .substring(0, characterLimit - 100) the same way we are doing for PR comment.

1. https://docs.github.com/en/rest/checks/runs?apiVersion=2022-11-28