Reinstate ipyparallel downstream tests #3626

Job	Run time
Test Minimum Versions	2m 52s
Test Lint	1m 12s
check_release	1m 51s
Make SDist	31s
Test Prereleases	2m 26s
test_docs	47s
test_without_debugpy (ubuntu-latest, 3.10)	2m 24s
build (ubuntu-latest, 3.10)	4m 45s
link_check	3m 38s
build (ubuntu-latest, 3.12)	4m 50s
build (ubuntu-latest, 3.13)	4m 48s
build (ubuntu-latest, 3.11)	4m 43s
build (windows-latest, 3.10)	7m 33s
build (windows-latest, 3.11)	7m 57s
build (windows-latest, 3.13)	9m 13s
build (macos-latest, 3.12)	4m 58s
build (windows-latest, pypy-3.10)	9m 0s
build (macos-latest, 3.11)	5m 19s
build (ubuntu-latest, pypy-3.10)	4m 36s
build (macos-latest, 3.10)	5m 25s
build (windows-latest, 3.12)	9m 2s
build (macos-latest, pypy-3.10)	5m 37s
build (macos-latest, 3.13)	4m 34s
Install from SDist and Test	2m 29s
coverage	10s
	1h 50m 40s

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