✅(app-desk) remove warning request not mocked

A request was not mocked in the test,
so the warning a warning was displayed.
This commit mocks the request to avoid the warning.

src/frontend/apps/desk/src/features/members/__tests__/MemberGrid.test.tsx

@@ -207,6 +207,8 @@ describe('MemberGrid', () => {
   });
 
   it('cannot add members when current role is member', () => {
+    fetchMock.get(`/api/teams/123456/accesses/?page=1`, 200);
+
     render(<MemberGrid team={team} currentRole={Role.MEMBER} />, {
       wrapper: AppWrapper,
     });