@Kiram_Tursun Netlify’s own, human response will be this:
If the site is in Bolt’s account, Netlify will not be able to delete it for you.
Bolt would need to delete it themsevles, if they refuse to, then Netlify cannot help.
Raise it with Bolt and speak to a human, not an AI.
If the site is in their account, then they can delete it from their account.