fix(fe): change finished contest exit to route contest problem list

[jimin9038]

Description

대회가 끝나서 exit 버튼을 누르면 contest main page가 아닌 contest problem list로 가도록 변경합니다. closes TAS-1062

Additional context

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[notion-workspace[bot]]

24-2 2차 배포 QA) Finished Contest Exit 버튼 클릭 시 contest problem list로 이동 요청