Implement Lookupable for Unit (#4497) #2760

Job	Run time
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / ci	21m 6s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / compile project with mill	3m 29s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / Formatting	1m 32s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / Benchmarking Sanity Check	2m 42s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / Integration Tests	12m 39s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / Build Mdoc & Website	6m 26s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / Standard Library (2.13.15)	1m 58s
ci (ubuntu-22.04, 8, 2.13.15, 2.4) / Test Scala-CLI Example / Build and Test	2m 36s
check tests	1s
all tests passed	1s
publish	7m 53s
Deploy Website	15s
	1h 0m 38s

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