tests: scalingo validation consistent test

[baruchiro]

Description:

Sometimes the tp of Scalingo is failing during the Github Actions workflow and after re-triggering it passed. I think the problem was when the generated example secret was ended with -, and combined with the Regex that expect for a word boundary \b, it was failed.

I think in any way it is better to use the common generateUniqueTokenRegex instead of wrapping the regex with \b.

Checklist:

• Does your PR pass tests?
• Have you written new tests for your changes?
• Have you lint your code locally prior to submission?

Original: gitleaks#1359