Test for analytical_derivatives: use mode_compute=9

This optimizer seems more robust accross different hardware (with other
optimizers, the algorithm does not converge to a local maximum, e.g. on the
runner "lupi").

(cherry picked from commit 39110b30)

tests/analytic_derivatives/fs2000_analytic_derivation.mod

@@ -81,7 +81,7 @@ varobs gp_obs gy_obs;
 
 options_.solve_tolf = 1e-12;
 
-estimation(order=1,mode_compute=5,analytic_derivation,kalman_algo=1,datafile=fsdat_simul,nobs=192,mh_replic=0,mh_nblocks=2,mh_jscale=0.8);
+estimation(order=1,mode_compute=9,analytic_derivation,kalman_algo=1,datafile=fsdat_simul,nobs=192,mh_replic=0,mh_nblocks=2,mh_jscale=0.8);
 estimation(order=1,mode_compute=5,mode_file=fs2000_analytic_derivation_mode,analytic_derivation,kalman_algo=2,datafile=fsdat_simul,nobs=192,mh_replic=0,mh_nblocks=2,mh_jscale=0.8);
 estimation(order=1,mode_compute=4,mode_file=fs2000_analytic_derivation_mode,analytic_derivation,kalman_algo=1,datafile=fsdat_simul,nobs=192,mh_replic=0,mh_nblocks=2,mh_jscale=0.8);
 estimation(order=1,mode_compute=4,mode_file=fs2000_analytic_derivation_mode,analytic_derivation,kalman_algo=2,datafile=fsdat_simul,nobs=192,mh_replic=0,mh_nblocks=2,mh_jscale=0.8);