Update list-untracked-repositories E2E to allow for 24 hours grace period

What does this MR do and why?

gitaly#4164 (closed) identifies a change where list-untracked-repositories now has a 24 hour grace period before reporting on repositories that may be on disk, but not recorded in the praefect database.

This change was introduced in gitaly!4449 (merged)

Updating E2E tests, to seed the data with a timestamp that exceeds this 24 hour threshold as otherwise they do not appear in the command output.

Closes #357454 (closed)

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