Change the way we find Polban participants on Atcoder ranking page

[saifulwebid]

As per February 12, 2022 (https://github.com/jtkencode/cp-leaderboard/actions/runs/1833723884), Atcoder does not support filtering the ranking page based on affiliation:

• This page now returns 404: https://atcoder.jp/ranking/all?f.Affiliation=Bandung+State+Polytechnic
• The main ranking page stopped showing filter controls: https://atcoder.jp/ranking.