Make test_persistent_gp_multitask_ax.py use gen_on_manager

Author: shuds13

libensemble/tests/regression_tests/test_persistent_gp_multitask_ax.py

@@ -2,21 +2,22 @@
 Example of multi-fidelity optimization using a persistent GP gen_func (calling
 Ax).
 
+Test is set to use the gen_on_manager option (persistent generator runs on
+a thread). Therefore nworkers is the number of simulation workers.
+
 Execute via one of the following commands (e.g. 5 workers):
-   mpiexec -np 5 python test_persistent_gp_multitask_ax.py
-   python test_persistent_gp_multitask_ax.py --nworkers 4 --comms local
-   python test_persistent_gp_multitask_ax.py --nworkers 4 --comms tcp
+   mpiexec -np 4 python test_persistent_gp_multitask_ax.py
+   python test_persistent_gp_multitask_ax.py --nworkers 3 --comms local
+   python test_persistent_gp_multitask_ax.py --nworkers 3 --comms tcp
 
 When running with the above commands, the number of concurrent evaluations of
-the objective function will be 3, as one of the three workers will be the
-persistent generator.
+the objective function will be 3.
 
-Requires numpy<2.
 """
 
 # Do not change these lines - they are parsed by run-tests.sh
 # TESTSUITE_COMMS: local mpi
-# TESTSUITE_NPROCS: 5
+# TESTSUITE_NPROCS: 4
 # TESTSUITE_EXTRA: true
 # TESTSUITE_OS_SKIP: OSX
 # TESTSUITE_EXCLUDE: true
@@ -63,6 +64,7 @@ def run_simulation(H, persis_info, sim_specs, libE_info):
 # Main block is necessary only when using local comms with spawn start method (default on macOS and Windows).
 if __name__ == "__main__":
     nworkers, is_manager, libE_specs, _ = parse_args()
+    libE_specs["gen_on_manager"] = True
 
     mt_params = {
         "name_hifi": "expensive_model",