refactor: remove unused updatePromises array from calculateMMR function

Author: ershisan99

src/utils/algorithms/calculateMMR.ts

@@ -149,7 +149,6 @@ export async function calculateNewMMR(
       oldMMR: number
       newMMR: number
     }> = []
-    const updatePromises: Promise<void>[] = []
 
     const playerUpdates: Array<{
       user_id: string
@@ -193,8 +192,6 @@ export async function calculateNewMMR(
       await updatePlayerMmrBulk(queueId, playerUpdates)
     }
 
-    await Promise.all(updatePromises)
-
     const usersNeedingRoleUpdate = await getUsersNeedingRoleUpdates(
       queueId,
       playerMMRChanges,