[WIP] fix multigrid agglomeration #9304

Job	Run time
Build SU2 (tsan) (ReverseOMP-tsan)	28m 47s
Build SU2 (tsan) (BaseOMP-tsan)	11m 30s
Build SU2 (asan) (BaseNoMPI-asan)	15m 46s
Build SU2 (ReverseMPI)	15m 50s
Build SU2 (BaseMPI)	13m 54s
Build SU2 (asan) (ReverseNoMPI-asan)	46m 26s
Build SU2 (ForwardMPI)	13m 1s
Build SU2 (ReverseNoMPI)	13m 34s
Build SU2 (ForwardNoMPI)	11m 1s
Build SU2 (BaseOMP)	9m 6s
Build SU2 (BaseNoMPI)	8m 20s
Build SU2 (ForwardOMP)	11m 12s
Build SU2 (ReverseTagNoMPI)	11m 39s
Build SU2 (ReverseOMP)	16m 36s
Tape Tests (serial_regression_AD.py)	2m 12s
Unit Tests (test_driver_AD)	54s
Unit Tests (test_driver)	53s
Regression Tests (serial_regression_AD.py)	5m 31s
Unit Tests (test_driver_DD)	1m 30s
Regression Tests (vandv.py)	3m 10s
Regression Tests (parallel_regression_AD.py)	10m 1s
Regression Tests (parallel_regression.py)	3h 47m 41s
Regression Tests (serial_regression.py)	3h 49m 15s
Regression Tests (tutorials.py)	8m 9s
Regression Tests (hybrid_regression_AD.py)	3m 55s
Regression Tests (hybrid_regression.py)	25m 7s
Thread Sanitizer Tests (hybrid_regression.py)	27m 14s
Thread Sanitizer Tests (hybrid_regression_AD.py)	11m 58s
Address Sanitizer Tests (serial_regression_AD.py)	6m 39s
Address Sanitizer Tests (serial_regression.py)	3h 48m 12s
	16h 59m 3s

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