CI: bump to MATLAB R2021b

(cherry picked from commit e4627641)
4 jobs for dynare-4.7 in 3 minutes and 8 seconds (queued for 48 seconds)
latest
Status Name Job ID Coverage
  Test
passed test_matlab #34325

00:00:53

passed test_octave #34337

00:01:48

passed test_old_matlab #34326

00:00:26

failed test_octave #34327

00:01:44