➖ Remove `unit` library due to increasing simulation runtimes. #1679

Job	Run time
ubuntu-20.04 with g++-10 (Debug mode)	10m 38s
ubuntu-20.04 with g++-10 (Release mode) C++20	15m 17s
ubuntu-20.04 with g++-11 (Debug mode)	11m 46s
ubuntu-20.04 with g++-11 (Release mode)	14m 58s
ubuntu-20.04 with clang++-10 (Debug mode)	6m 59s
ubuntu-20.04 with clang++-10 (Release mode)	15m 29s
ubuntu-20.04 with clang++-11 (Debug mode)	7m 11s
ubuntu-20.04 with clang++-11 (Release mode)	12m 49s
ubuntu-20.04 with clang++-12 (Debug mode)	7m 55s
ubuntu-20.04 with clang++-12 (Release mode)	16m 21s
ubuntu-22.04 with g++-10 (Debug mode)	11m 39s
ubuntu-22.04 with g++-10 (Release mode)	20m 20s
ubuntu-22.04 with g++-11 (Debug mode)	10m 49s
ubuntu-22.04 with g++-11 (Release mode)	18m 37s
ubuntu-22.04 with g++-12 (Debug mode)	14m 54s
ubuntu-22.04 with g++-12 (Release mode)	22m 41s
ubuntu-22.04 with clang++-11 (Debug mode)	6m 21s
ubuntu-22.04 with clang++-11 (Release mode)	12m 13s
ubuntu-22.04 with clang++-12 (Debug mode)	6m 56s
ubuntu-22.04 with clang++-12 (Release mode)	15m 56s
ubuntu-22.04 with clang++-13 ( mode)	14m 38s
ubuntu-22.04 with clang++-14 ( mode)	12m 19s
ubuntu-22.04 with clang++-15 ( mode)	12m 14s
	4h 59m 0s

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