Fix arpack solver #496

Job	Run time
ubuntu_latest_autotools	14m 9s
ubuntu_latest_cmake	4m 39s
ubuntu_latest_cmake_install	10m 33s
macos_latest_cmake	6m 21s
ubuntu_latest_autotools_ilp64	1m 51s
ubuntu_latest_autotools_install	18m 31s
ubuntu_latest_cmake_python	11m 14s
macos_latest_autotools	8m 1s
macos_latest_cmake_python	6m 47s
MinGW-w64 UCRT64 INTERFACE64=ON/MPI=OFF	10m 8s
MinGW-w64 UCRT64 INTERFACE64=OFF/MPI=ON	9m 56s
MinGW-w64 UCRT64 INTERFACE64=OFF/MPI=OFF	9m 48s
MinGW-w64 CLANG64 INTERFACE64=ON/MPI=OFF	7m 57s
MinGW-w64 CLANG64 INTERFACE64=OFF/MPI=ON	8m 33s
MinGW-w64 CLANG64 INTERFACE64=OFF/MPI=OFF	8m 17s
	2h 16m 45s

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