Adding open AI Token rule

What does this MR do?

This MR extends on the work implemented in !221 (closed) by @fsieverding.

In addition to the work added in !221 (closed), this MR

• adds an fake Open AI API key to the integration specs
• updates the Open AI regular expression to include \b and the start and end
• Fixes an issue in the gitleaks TOML unit test that ensures the pattern password="TOKEN" matches.

What are the relevant issue numbers?

NA

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests updated/added for this feature/bug
• Job definition updated, if necessary
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  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer