piece picker - switch to useCallback() to satisfy linter

Author: mfwolffe

components/student/piecePicker.js

@@ -4,6 +4,7 @@ import { Form, Nav, Spinner } from 'react-bootstrap';
 import { useQuery } from 'react-query';
 import { useCallback } from 'react';
 import { getStudentAssignments } from '../../api';
+import { useCallback } from 'react';
 
 function PiecePicker() {
   const router = useRouter();