fix(score): multiroom player skill calculation

[Ai0796]

Changed multi room skill calculation to work off the post anniversary equation instead of the pre anniversary equations. Should fix values being off in high skill and low skill scenarios

Description

Changed skill equation from: To:

Related Issue

https://github.com/Sekai-World/sekai-viewer/issues/403

Motivation and Context

Fixes score calculation (and event point calculation) for multiplayer as low skill teams would see noticable fewer event points while high skill teams would see noticably higher event points

How Has This Been Tested?

• [ ] Chrome (Desktop)
• [ ] Chrome (Mobile)
• [ ] Firefox (Desktop)
• [ ] Firefox (Mobile)
• [ ] Safari (Desktop, optional)
• [ ] Safari (iPhone, optional)
• [ ] Safari (iPad, optional)

Screenshots (if appropriate):