Increase C 2x2x1 Gaussian variance tolerance in short test #7051

Job	Run time
linux (GCC9-NoMPI-Debug-Real)	16m 4s
macos (macOS-GCC14-NoMPI-Real)	12m 34s
linux (GCC9-NoMPI-NoOMP-Real)	14m 59s
spack-centos-stream (GCC11-NoMPI-Debug-Real)	18m 52s
linux (GCC9-NoMPI-NoOMP-Complex)	15m 7s
spack-centos-stream (GCC11-NoMPI-NoOMP-Real)	17m 37s
linux (GCC9-MPI-Sandbox-Real)	3m 35s
spack-centos-stream (GCC11-NoMPI-NoOMP-Complex)	17m 42s
linux (GCC9-NoMPI-Sandbox-Complex)	5m 28s
spack-centos-stream (GCC11-NoMPI-Sandbox-Real)	4m 7s
linux (GCC9-MPI-Gcov-Real)	25m 9s
linux (GCC9-MPI-Gcov-Complex)	25m 33s
linux (GCC12-NoMPI-Werror-Real)	18m 17s
linux (GCC12-NoMPI-Werror-Complex)	18m 21s
linux (GCC12-NoMPI-Werror-Real-Mixed)	17m 37s
linux (GCC12-NoMPI-Werror-Complex-Mixed)	18m 37s
linux (Clang14-NoMPI-ASan-Real)	24m 49s
linux (Clang14-NoMPI-ASan-Complex)	23m 50s
linux (Clang14-NoMPI-UBSan-Real)	23m 51s
linux (Clang16-NoMPI-Offload-Real)	22m 48s
linux (Clang16-NoMPI-Offload-Complex)	22m 22s
	6h 7m 19s

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