Refactor organization and user management components/tests for simplification and improved clarity

- Removed unused properties (`slug`, `is_active`, etc.) in organization and user-related components and test data.
- Simplified function data typing by removing redundant `any` usage.
- Updated `params` in `OrganizationMembersPage` for Promise resolution and async handling.
- Cleaned up unused variables and streamlined form handling in `AddMemberDialog`.

frontend/src/components/admin/users/UserListTable.tsx

@@ -76,7 +76,6 @@ export function UserListTable({
 
   const allSelected =
     users.length > 0 && users.every((user) => selectedUsers.includes(user.id));
-  const someSelected = users.some((user) => selectedUsers.includes(user.id));
 
   return (
     <div className="space-y-4">