Fix missing private clauses in 3D viscous GPU loops #4553

Job	Run time
Lint Gate	1m 16s
Detect File Changes	10s
Github (ubuntu, mpi, debug, true)	6m 35s
Github (macos, mpi, debug, false)	6m 38s
Github (ubuntu, mpi, no-debug, false)	6m 36s
Github (ubuntu, mpi, no-debug, true)	6m 37s
Oak Ridge \| Frontier (gpu-acc)	1s
Oak Ridge \| Frontier (AMD) (cpu)	1s
Github (ubuntu, mpi, debug, false)	6m 36s
Github (ubuntu, no-mpi, single, no-debug, false)	6m 36s
Github (macos, mpi, no-debug, false)	5m 7s
Oak Ridge \| Frontier (AMD) (gpu-omp)	1s
Georgia Tech \| Phoenix (cpu)	1s
Oak Ridge \| Frontier (gpu-omp)	6m 23s
Oak Ridge \| Frontier (cpu)	1s
Georgia Tech \| Phoenix (gpu-omp)	1s
Georgia Tech \| Phoenix (gpu-acc)	6m 23s
	59m 3s

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