Network error shown when creating ranking round without threshold selection

[Oyelakin-Mercy]

When creating a ranking round, the threshold dropdown was shown but not validated, and submitting without selecting one caused a network error from the backend.

[Anujkumar9081]

I'll work on fixing the threshold validation issue. Let me start investigating and submit a PR soon.

[Harshita-kothari]

Hi, I would like to work on this issue. Could you please assign it to me?