Set internal bots profiles to be private and confirmed

What does this MR do and why?

I've recently added duo_code_review_bot as a part of #464786 (closed) and noticed that some of our bots have public profiles and some don't. Also, noticed that some are marked as unconfirmed which makes it look a little strange.

Examples:

• https://gitlab.com/alert-bot -> unconfirmed and private
• https://gitlab.com/support-bot -> confirmed and public
• https://gitlab.com/GitLab-Llm-Bot -> confirmed and private

I was looking for an answer, but wasn't able to find any explanations for these inconsistencies and I believe it was just an oversight. Therefore, I've created this MR to make them consistent to avoid further confusion in the future.

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