Clear and concise description of the problem

Follow-up of #9952.

Use .vitest convention in blob-reporter.

Suggested solution

Replace .vitest-reports with .vitest/blob. Ideally it should use vitest.createReport() API internally.

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that requests the same feature to avoid creating a duplicate.