Subshells implemented using tornado event loops on 6.x branch #3361

Job	Run time
Test Lint	1m 1s
check_release	1m 41s
build (ubuntu-latest, 3.9)	3m 18s
link_check	3m 34s
Make SDist	25s
build (ubuntu-latest, 3.13)	3m 29s
build (windows-latest, 3.9)	6m 39s
test_docs	40s
Test Minimum Versions	3m 27s
build (windows-latest, 3.13)	8m 32s
Test Prereleases	2m 59s
build (macos-latest, 3.9)	3m 36s
test_without_debugpy (ubuntu-latest, 3.9)	2m 53s
build (macos-latest, 3.13)	3m 3s
build (ubuntu-latest, pypy-3.9)	4m 54s
build (macos-latest, 3.10)	3m 29s
build (ubuntu-latest, 3.11)	3m 12s
build (ubuntu-latest, 3.12)	3m 42s
Install from SDist and Test	2m 57s
coverage	0s
	1h 3m 31s

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