Switch to ReTestItems.jl. #608

Job	Run time
Julia release-1.8 - ubuntu-latest - x64	15m 29s
Julia release-1.8 - macOS-latest - x64	19m 4s
Julia release-1.9 - ubuntu-latest - x64	24m 11s
Julia release-1.9 - macOS-latest - x64	22m 53s
Julia release-1.9 - windows-latest - x64	24m 56s
Julia master - ubuntu-latest - x64	22m 22s
Julia master --opaque-pointers - ubuntu-latest - x64	25m 7s
Documentation	54s
Julia 1.8 - ubuntu-latest - x64	1m 34s
Julia 1.8 - macOS-latest - x64	2m 45s
Julia 1.8 - windows-latest - x64	4m 43s
Julia 1.9 - ubuntu-latest - x64	1m 42s
Julia 1.9 - macOS-latest - x64	2m 32s
Julia 1.9 - windows-latest - x64	4m 7s
Julia nightly - ubuntu-latest - x64	2m 17s
Julia nightly - macOS-latest - x64	2m 50s
Julia nightly - windows-latest - x64	33m 10s
Julia nightly --opaque-pointers - ubuntu-latest - x64	1m 52s
Julia nightly --opaque-pointers - macOS-latest - x64	2m 40s
Julia nightly --opaque-pointers - windows-latest - x64	33m 25s
	4h 8m 33s

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